Event Email Deliverability: The Complete Guide to Getting More Emails into the Inbox

Event Email Deliverability Starts with Learning the Laws

Before you send a single message, you need to learn the laws related to commercial email marketing. This article focuses on U.S. and Canadian laws, but be sure to do your due diligence and learn laws in other countries if you plan to send email marketing messages elsewhere.

In the United States, the CAN-SPAM Act of 2003 is the legislation for commercial email, while CASL sets the legal rules in Canada.

CAN-SPAM Act of 2023

CAN-SPAM stands for Controlling the Assault of Non-Solicited Pornography And Marketing. The legislation applies to commercial email and went into effect on January 1, 2004. It includes fines of up to $53,088 per email for violations as of 2026.

Key requirements of the law include:

• You must give recipients a way to unsubscribe
• Emails must include your physical address
• Emails cannot include deceptive headers or subject lines
• If someone else is sending bulk emails on your behalf, you’re responsible for monitoring what they’re doing.

CASL

CASL stands for Canada’s Anti-Spam Legislation and applies to commercial electronic messages (CEMs). If you commit a violation under CASL, you may be required to pay an administrative monetary penalty (AMP). The maximum amount of an AMP for an individual is $1 million per violation and $10 million per violation for a business as of 2026.

Under CASL, you must be able to prove you have express or implied consent to send commercial electronic messages (including emails) to recipients. If you use third parties to send email messages for you, you need to monitor what they’re doing on your behalf, because both you and the third party could be liable for violations.

The following are required in every CEM:

• The name of the person sending the message, and on whose behalf the message is sent, if it’s different
• Sender contact information (mailing address and either a phone number or an email address)
• An easy way for recipients to unsubscribe at no cost
• No deceptive header information, sender information, or subject lines

Event Email Deliverability Depends on the ESP Gatekeepers

Here’s a really important distinction that you have to understand if you want your event email marketing efforts to deliver the best results:

Just because an email marketing software shows that your message was delivered, doesn’t mean it actually made it to recipients’ inboxes.

The above statement is true no matter what email marketing platform you use to send your messages. That’s because your email marketing messages have to get through the email service provider (ESP) gatekeepers to make it to the inbox.

Email service providers (also referred to as mailbox providers, email clients, or similar terms) – like Google (Gmail), Apple (Apple Mail), Microsoft (all Outlook and Hotmail versions), Yahoo!, AT&T mail, AOL, and so on – are the gatekeepers for every email inbox.

When your email marketing software shows a message was delivered to a recipient, that just means it was delivered to the ESP gatekeeper. It’s doesn’t tell you what the ESP gatekeeper decided to do with the message after they got it.

After receiving your message, ESPs use elaborate algorithms built over many years (and updated frequently) with thousands of data points to analyze your message and decide where to send it. These algorithms not only look for words and phrases, but they also learn from users by analyzing all messages received and looking for patterns in emails. These filters learn based on what recipients do and do not mark as spam.

After analyzing your message, ESPs could:

• Send it to the inbox
• Send it to the spam/junk folder
• Block it and not send it to the recipient at all

ESPs are extremely protective of people’s email inboxes, and it’s not easy to get past them when you’re sending bulk email messages (defined as messages sent to 100 or more recipients).

Each ESP’s goal is simple. Keep messages people don’t want out of their inboxes.

But the ways they keep messages people don’t want out of inboxes can vary.

Google is known among email marketers to be the toughest gatekeeper, which is unfortunate since the vast majority of email users are using Google/Gmail. Note that Gmail/Google includes both personal Gmail accounts (@gmail.com) and business Gmail accounts (e.g., @companyname.com – accounts that use the business’s domain in the email address but Google provides access to the email messages).

In addition to using spam filters and other methods to keep unwanted messages out of inboxes, Google could also send messages to the Promotions tab, where recipients are less likely to see them. 

How ESP Gatekeepers Decide if a Message Goes to the Inbox

Email service providers use many methods to analyze messages and decide whether to send them to the inbox (or promotions tab for Gmail), spam/junk folder, or block them entirely. That means every ESP has its own opinion of you as a sender, which is why one ESP may send your messages to the inbox while another sends them to the junk folder.

These methods are mostly proprietary, so email marketers don’t know the exact factors that affect event email deliverability. However, experts have been tracking deliverability for a long time. Their insights combined with the information ESPs have shared publicly provides a roadmap to the inbox that you can follow.

Based on what is known to date, there are three key factors that affect email deliverability:

1. Technical
2. Sending history
3. Content

Together, these factors are used by ESPs to determine your sender reputation, which includes both your IP reputation and domain reputation.

Your IP reputation is tied to the server or IP address that your messages are sent from. If you’re sending from an email marketing software, you’ll likely be sending from a shared IP address, which means the sending behaviors of all senders using that IP address affect the reputation. Email marketing providers work very hard to keep the reputations of the IP addresses they use high.

Your domain reputation is tied to the domain that your messages are sent from (e.g., yourcompany.com). If you’re sending from your own domain, then you’re 100% responsible for your domain reputation. If you’re sending from a shared domain through an email marketing software provider, then every sender whose messages are sent through that domain affects the domain reputation. If you’re sending through a shared domain, you need to do your part to protect the reputation of that domain or every sender using it – including you – could see reduced deliverability.

The way to keep a high sender reputation is to be a good sender who sends messages that people actually want without any technical or content spam triggers.

Let’s take a closer look at each of the three deliverability factors.

1. Technical Factors that Affect Event Email Deliverability

There are two types of technical factors that affect event email deliverability: technical settings and spam traps.

Technical Settings

To get into inboxes, you have to prove you’re who you say you are. ESPs analyze a variety of technical settings to ensure every sender is exactly who they claim to be. Therefore, the first step to get into inboxes is to make sure you have all of your technical settings configured to prove who you are to ESPs, including:

• DNS (Domain Name System): Your email address is matched to your domain name, and a DNS text record is used to match it to a sending IP address.
• SPF (Sender Policy Framework): This text file shows email clients the IP addresses that are allowed to send mail on behalf of your domain.
• DKIM (DomainKeys Identified Mail): This is a text file that shows messages aren’t altered in between the sending and recipient servers.
• CNAME (Canonical Name): This is a text record that connects an alias name to a true name (for example, www.yourcompany.com and yourcompany.com).
• DMARC (Domain-based Message Authentication, Reporting and Conformance): This is a policy that tells email clients messages are protected by SPF and/or DKIM.

It’s also best to ensure your sender domain (e.g., yourcompany.com) matches your sender email address (e.g., [email protected]).

If you’re sending through a shared domain via a third party (e.g., your email marketing software provider), you may not be able to match your sender email address to the sender domain. However, you should make sure they have all of the settings in the list above configured properly.

If you’re sending from your own domain and don’t know how to configure these settings, ask your email marketing software provider for help.

Spam Traps

There are two types of spam trap email addresses that should be removed from your email marketing lists immediately:

• Recycled Spam Traps: These are email addresses that were once valid and actually belonged to someone, but they’re now abandoned and have become spam addresses.
• Honeypot (Pristine) Spam Traps: These email addresses never belonged to anyone. ESPs create them and hide them on websites for one reason – to catch spammers using robots to crawl websites and scrape email addresses.

If you send a message to just one spam trap email address, your deliverability will immediately go down. That’s just one of the reasons why it’s always best to build your own subscriber lists and keep them clean rather than scraping email addresses from the web or buying email lists.

2. How Sending History Affects Event Email Deliverability

Sending history is by far the most important factor that ESPs use to determine where to send your email messages. The most important factors ESPs analyze to determine how your sending history affects your sender reputation are:

• Recipient engagement
• Sending consistency
• Spam complaints

Recipient Engagement

Your sending history is significantly impacted by how people have engaged with your messages in the past. In fact, many email marketing experts believe it’s the most important factor affecting sender reputation.

ESPs think if you’re sending messages that people want, they’ll positively engage with your messages by opening them right away, clicking on links inside, forwarding them, filing them in folders, and so on.

On the flip side, if recipients never open your messages, delete them without opening them, or worse, mark them as spam or junk or block you as a sender, ESPs think you’re sending content that people don’t want.

Remember each ESP’s goal is to keep messages people don’t want out of their inboxes.

If people don’t positively engage with the messages you send, ESPs will notice, your deliverability will go down, and more and more of your messages will start going to the spam folder.

To keep positive engagement high, you need to avoid sending generic email messages to large lists of recipients (i.e., spray and pray). Instead, use audience segmentation to break your list into smaller groups of people with similar interests, demographics, or behaviors, and then, send laser-focused content that each target audience would actually want to receive.

Yes, it’s easier to send one email to everyone announcing tickets are on sale for your event, but engagement will definitely be lower than if you segment your list and send more targeted messages to different audiences (e.g., previous attendees, families, local subscribers, out-of-town subscribers, and so on). ESPs are watching, and your future deliverability could depend on taking the extra steps to boost content relevancy today.

Sending Consistency

Sending consistency relates to both the schedule and volume of email messages you send. ESPs like consistency, because to them, predictability is safe. If they had their preferences, email marketers would send messages at exact same day and time each week and to the exact same number of recipients.

Unfortunately, that’s not how email marketing usually works – and certainly not for event marketing.

To make ESPs happy with your sending consistency, try to establish a pattern for sending your bulk email campaigns. Choose a day of the week and time of day, and try to stick to it as much as you can. Importantly, avoid large time gaps between bulk sends.

For sending volume, the key to making ESPs happy is to avoid big changes in the number of messages you send. The unofficial rule is to send to no more than double the number of recipients you sent to in your last email.

What happens if you need to suddenly start sending to a large list of people? For example, if you organize an annual event, you may go months without sending any emails to your list at all.

First, don’t disappear. Try to touch base with the people on your list throughout the year. Second, do a domain warmup before you send any messages to your entire list. A domain warmup is a safe method to ramp up your sending volume without hurting your sender reputation and your deliverability.

Even if you send from a shared domain, it makes sense to do a warmup, because you don’t know what other senders using that domain have been doing. You don’t want to be the reason the domain reputation tanks!

Following is a simple domain warmup schedule that many senders have success with:

1. Phase 1: Send a message to addresses of people you know. It should include text as well as one image (to track opens) and one link. These addresses could be coworkers, friends, family, etc. Let them know the message is coming, and tell them to open it and click on a link inside it when they receive it. Once you get a 20% open rate, move to phase 2.
2. Phase 2: Send a message to 100-150 addresses of people who have engaged with your messages the most in the past. Again, include text, an image, and a link. If you get 15% of fewer opens, wait one week and repeat phase 2. If you get a 20% open rate, move to phase 3.
3. Phase 3: Send to 200-300 addresses on your list. If you get 15% or fewer opens, wait one week and repeat phase 3. If you get a 20% open rate, you can continue sending on a weekly basis but send to no more than double the addresses in your previous send.
4. Phase 4 and beyond: Continue doubling each week until you reach your full volume. Don’t increase your volume until you get a 20% open rate.
5. Caution: If more than 30 days lapse between any phase, start over at phase 1.

There are many different schedules that you can follow to do a domain warmup. Some are more aggressive and some require daily sending rather than weekly sending. Work with your email marketing software provider to determine the best warmup schedule for your audience and sending goals.

Spam Complaints

Email service providers don’t care how many people unsubscribe from your messages, but they sure do care about how many people mark your messages as spam.

Unfortunately, not all ESPs directly report spam complaints to senders. For example, Google does not.

Your email marketing platform probably shows you a spam percentage for each message you send, but that only tracks the number of people who clicked the spam button (not including Google). It doesn’t tell you the percentage of messages that actually landed in the spam/junk folder or were blocked entirely.

Bottom line, you never want a recipient to mark your email messages as spam. In fact, ESPs want you to get no more than 1 spam complaint for every 1,000 email messages you send. That equates to a 0.1% spam complaint rate. If you hit that threshold, your deliverability will start to suffer, and if your spam complaint rate hits 0.3%, most (if not all) of your email messages will go to spam folders or be blocked entirely.

Here’s how deliverability is affected based on your spam complaint rate:

• Less than 0.1% (fewer than 1 complaint per 1,000 emails): This is the industry standard you need to stay below to keep your domain reputation high and ensure your messages keep landing in inboxes.
• 1%-0.29% (1 to 2 complaints per 1,000 emails): If your spam complaint rate falls in this range, deliverability will degrade and some of your email messages will start going to the spam or junk folder.
• 3% or higher (3 or more complaints per 1,000 emails): Once your spam complaint rate hits 0.3%, most or all of your messages will go to spam or be blocked entirely. Crossing this threshold is a violation of some ESP’s public bulk sender policies, so your domain reputation will immediately tank. It’s possible to fix it, but the process isn’t easy.

Keep in mind, the spam complaint rate is calculated by dividing the number of complaints received by the number of emails that were successfully delivered. If you send 1,000 email messages but only 800 of those messages are actually delivered (e.g., 200 bounced), then the spam complaint rate is calculated by dividing the number of spam complaints by the number of delivered messages. In this example, your spam complaint rate would be 1.25%, and your deliverability would go down.

Another thing to understand about spam complaints is that new and dormant domains have lower spam complaint thresholds. New domains with no sending history are unknown to ESPs, so they don’t have reputations yet. Similarly, domains that haven’t sent a bulk message in more than 30 days are considered dormant and have no reputation. ESPs don’t know if they can trust the domain yet. For new and dormant domains, a spam complaint rate as low as 0.05% (one complaint per 2,000 emails) can cause reputation and deliverability problems.

That’s why the domain warmup explained earlier is so important for new and dormant domains. You have to prove you’re a trustworthy sender from the first bulk send and keep doing so from then on.

People mark messages as spam when they’re not relevant to them. Keep your list clean, segment your audience, and send content people actually want to keep your spam complaints low.

3. How the Content Inside Your Messages Affects Event Email Deliverability

There are many content-related spam triggers that can directly impact whether your email marketing messages land in inboxes, other Google tabs, or the spam/junk folder. If your sender reputation is great, then you can get away with including some content spam triggers in your messages. However, as soon as your reputation dips, including them could be the difference between making it to the inbox or not.

ESPs don’t provide a full list of content-related spam triggers, but they do share some information. From what the email marketing industry has been able to determine, you should avoid including anything in your messages that could alert ESPs to the following content spam triggers:

• Including Re: or Fw: in your subject line when the message is not a reply or forward
• Sending a large email size over 100kb
• Including more images than text in your message (make sure 60% is text and no more than 40% is images)
• Using link shorteners
• Using excessive punctuation or special characters in the subject line
• Using irregular capitalization in the subject line (e.g., “Get Your FREE UPGRADE Pass to the Fair)
• Including excessive grammar and spelling errors in the subject line or message content
• Using too good to be true words and claims like free, make money, 100%, and so on
• Using misleading subject lines or content
• Including an excessive number of links compared to the total amount of text in your message
• Including links to too many different domains
• Including links to low authority domains and sites with poor reputations
• Embedding videos or forms in the message content
• Attaching documents to the message
• Including poorly-coded HTML, Javascript, or Flash in the message
• Hiding text in the message content
• Sending duplicate content or subject lines that you’ve sent in the past either to the same audience or different audiences (someone may have already marked that content or subject line as spam, so any new messages with all or part of that content or subject line will go to spam)
• Not including an obvious unsubscribe link that makes it easy to unsubscribe instantly
• Not including your physical address in the message
• Overly salesy or promotional content

Another important content factor that can affect deliverability isn’t related to spam triggers; it’s related to tracking open rates. ESPs track opens using an image pixel that only fires when someone opens your message and there is an image in it. If there isn’t an image, the open isn’t tracked, and your engagement rate will go down. That can negatively affect your sender reputation, which can hurt deliverability.

Therefore, always include at least one image in your bulk email messages (even if it’s just your logo in the signature block) because it affects your open rates.

Note that the image pixel isn’t perfect. Some ESPs block images from loading when a message is opened, so the recipient has to click a link saying they want to see the images in order for them to load.

As of April 2026, Google started prefetching images, so tracking pixel opens is now unreliable. Some are counted even when a message isn’t opened, and some aren’t detected at all.

Apple also preloads images, so every message is tracked as opened regardless of whether the recipient actually opened it or not.

The lesson is this – open rate isn’t a reliable metric of engagement, so use it for guidance only. Focus on consistently sending relevant content to the right audiences without content spam triggers, and your deliverability should continue without any problems or delays.

How to Monitor and Protect Your Deliverability

If you’re sending email marketing messages through a shared IP and domain, then you won’t be able to access reputation-related data. Most event marketers use an email marketing software to send bulk email messages. If the provider hasn’t asked you to set up your own domain for sending through their platform, then you’re probably sending through a shared domain. This is the case for most events.

When you’re sending from a shared IP and domain, a reputable email marketing application provider will closely monitor IP and domain reputation to ensure its users’ messages make it to inboxes. However, you have to do your part to be a good sender and protect that reputation and deliverability. If the email marketing platform provider contacts you to discuss your prior email sends and suggests improvements to ensure future deliverability, follow their recommendations. Your future deliverability will be better if you do.

If you’re sending through your own domain, Google is the only ESP that offers tools to track your spam complaints and deliverability-related problems using Google Postmaster Tools. Once you set it up, you can access delivery and spam reports to help you identify deliverability problems before they get too big to fix.

If your reputation and deliverability start to dip, you can usually fix it with a domain warmup. However, if your spam complaint rate goes over the threshold and your reputation and deliverability tank, you may have to go through a more intense domain remediation process to repair your reputation or start sending from a new domain.

The Key to Event Email Deliverability Success

The secret to ensuring your event email marketing messages make it to inboxes now and in the future is to continuously show ESPs that you’re a sender. That means your technical settings have to be configured correctly, you need to build a great sending history, and you need to avoid spam triggers.

Segment your audience and only send messages people want. If they didn’t engage with the last five messages you sent, remove them from your list. Remove email addresses that bounce from your list. If you have a gap in sending, do a domain warmup, and avoid volume spikes.

Finally, make it easy to unsubscribe, because it’s better for someone to unsubscribe if they’re not interested than to click the spam button.

You never want ESPs to think you’re using the old spray and pray technique, meaning you send the same message to tons of people and hope someone bites. That’s a ticket to the spam folder, and once you land in the spam folder, it can be very hard to get out.

Frequently Asked Questions about Event Email Deliverability

1. What is email deliverability, and why does it matter for event marketing?

Email deliverability is the ability of your marketing emails to reach recipients’ inboxes rather than spam folders or being blocked. It’s important for event marketing because poor deliverability means fewer potential ticket buyers see your announcements, ticket offers, reminders, and event updates. Improving deliverability helps more people receive your messages, which can ticket sales and event marketing ROI.

2. Why are my event marketing emails going to spam?

Your event marketing emails may go to spam because of poor sender reputation, incorrect email authentication settings, low recipient engagement, high spam complaint rates, inconsistent sending volumes, or content that triggers spam filters. Sending generic messages to large lists of unengaged subscribers can also hurt deliverability.

3. What’s the difference between email delivery and email deliverability?

Email delivery means your message was successfully accepted by the recipient’s email service provider. Email deliverability refers to whether that message actually reaches the recipient’s inbox. An email marketing platform may report a message as delivered even when Gmail, Outlook, Yahoo, or another email service provider places it in the spam folder. That’s why a high delivery rate doesn’t necessarily mean your audience is seeing your event marketing emails.

4. What is a good spam complaint rate for event marketing emails?

A good spam complaint rate is below 0.1%, or fewer than one complaint per 1,000 delivered emails. Gmail recommends keeping spam rates below 0.1% and avoiding rates of 0.3% or higher. Excessive spam complaints can damage your sender reputation and deliverability, which means fewer of your messages will make it to inboxes.

5. How can I improve email deliverability for my event?

Start by ensuring your technical settings are configured correctly. Next, keep your list clean, segment your audience, and send content that’s relevant to each group. Maintain a reasonably consistent sending schedule, avoid sudden volume spikes, and keep spam complaints low. Monitor campaign performance and follow your email marketing provider’s recommendations to protect your sender reputation.

6. How often should event organizers send marketing emails to maintain good deliverability?

Event organizers should maintain a reasonably consistent email schedule rather than disappearing for months and suddenly sending large campaigns. For annual events, consider sending occasional newsletters, event announcements, and other relevant updates throughout the year. The ideal frequency depends on your audience and event schedule.

7. What is a domain warmup, and when should an event marketer use it?

A domain warmup is the process of gradually increasing email sending volume to establish or rebuild a positive sender reputation. It’s especially useful when you’re sending from a new domain, returning after a long period without email campaigns, or preparing to send significantly more messages than usual. Start with your most engaged subscribers and gradually expand your audience while monitoring performance. Your email marketing provider can recommend an appropriate warmup schedule.

8. Can audience segmentation improve event email deliverability?

Yes. Audience segmentation can improve email deliverability by helping you send more relevant messages to subscribers who are likely to engage. For example, you could send different campaigns to past attendees, previous ticket buyers, local subscribers, families, and people interested in specific event activities. Relevant messages are more likely to generate positive engagement and fewer spam complaints, which can help protect your sender reputation and protect future deliverability.

Your Next Steps to Better Event Email Deliverability

If you’re ready to improve your email marketing deliverability and results, schedule a TicketReach demo, and learn how the email marketing platform built specifically for live events can help you sell more tickets and consistently communicate with your audience.