10 Reasons You Might Have Email Delivery Challenges and How to Avoid Them

Estimated reading time: 10 minutes

Given the rapidly changing landscape of email marketing, it can be difficult for email marketers to maintain their email deliverability at a high level. This article explains the most common errors and overlooked things related to email delivery and provides advice on how to do it right to avoid email delivery challenges.

1. Building an Email List Improperly.

Buying, scraping or renting email lists are not considered permission-based list building practices and are prohibited by law regulations in many countries. Your deliverability will suffer if you get signups by methods other than asking for an explicit permission for regular marketing communications. 

Furthermore, you may end up with various email deliverability challenges if you apply technically allowed but unhealthy practices such as giveaways, content downloads, account creations, previous purchases.

Gathering email recipients using a prohibited or an unhealthy method will soon lead to email delivery challenges such as:

• Blocked emails;
• Emails filtered out to Spam;
• Emails reported as spam by users;
• Low sender reputation.

In the context of email marketing, creating a strong, permission-based list of people who have specifically chosen to receive your email communications is the prerequisite of a high deliverability and response rate.

2. Using a Free Domain for Marketing Emails.

Sending marketing or commercial emails from an email address set up on a free domain with Gmail, Yahoo, or Outlook is not a good idea. This is due to the fact that if you send commercial emails from an email address hosted on their domain, Yahoo, Gmail, and other mailbox providers will automatically flag your emails as spam or ban them completely.

Utilizing your private domain will not only assist in avoiding needless email delivery challenges like spam filtering or message blocking, but it will also make your domain recognized, increasing the possibility that your future emails will be seen, opened, and acted on.

3. Sending Marketing Emails from the Main Domain.

Best email marketing practices suggest avoiding sending marketing or commercial messages from an email address set up on your organizational domain. This recommendation is due to the fact that marketing emails may generate spam complaints. Furthermore, domains sending email messages are more susceptible to spoof attacks. Exposing your main domain to these vulnerabilities puts at risk your whole brand and other email communications. 

With that said, setting up a subdomain on your main domain, creating a mailbox on a subdomain dedicated to marketing and commercial deliveries would be a good alternative. At the same time, you can send messages not related to marketing offers from your main domain. These communications can include transactional messages, service updates, account or billing notifications, etc.

4. Sending from an Unauthenticated Domain. 

Building a reputation of a decent, respectable sender with inbox providers and recipients is a major component of email deliverability. Inbox providers can verify the authenticity of your emails thanks to available email authentication protocols. It’s crucial to configure SPF, DKIM, and DMARC records for a domain before it starts sending any emails. 

Mailbox providers will either reject your emails completely or route them directly to spam when you send them without authentication. This will negatively impact your sending reputation and cause email deliverability challenges over time.

Thanks to monitoring tools like GlockApps DMARC Analyzer, you can process DMARC reports on auto-pilot and instantly determine email authentication problems. Additionally, you control the email volume sent from your domain and can easily spot any domain spoofing facts.

5. Skipping a Warmup Phase.

Email marketing is all about sender reputation, which determines success or failure of your email communications. Every new domain and IP address intended to send emails needs to go through a good warmup process to gain a sender reputation. 

A domain or IP warmup implies starting with a small number of emails and increasing the volume every day until you achieve a desired number per day. Depending on this, a warmup phase can take from several weeks to several months. To do it right, it’s recommended to use tools dedicated to do a domain or IP warmup as they have a good email database to send emails on behalf of a domain to and interact with them.

6. Sending Inconsistently.

While brand recognition is crucial, email marketers frequently ignore the importance of expectations. Establishing expectations among your subscribers improves engagement, which in turn improves deliverability. Sending emails infrequently can make the recipients forgetful. 

Establishing a regular mailing schedule – daily, weekly, or monthly, depending on your audience and content – will increase subscriber expectations and boost your visibility in general. 

A good practice is to set the sending frequency right on the subscription form or state it clearly in a welcome email in order the subscribers know when to expect an email from your brand.

7. Sending Too Large Emails.

Although it has a far less effect than things like sender reputation or list management, the size and content of your emails can have an impact on deliverability. Spammers and phishers may use emails that are primarily made up of one large image and a link, or that have a lot of photos but little content. Sending emails in this manner puts you at risk of having them marked as spam.

To avoid this, make sure your emails are logical and interesting by designing them with a balanced image-to-text ratio. This is particularly crucial if an email client blocks the images by default, as many clients do for security reasons.

On the other side, some mailbox providers consider it hazardous when a marketing email contains too much information. If your email gets too long, certain inboxes may also clip it, hiding portions of it until the recipient clicks to reveal the entire message.

More reasons for limiting the amount of information in your emails are:

• Mobile views. Email viewing on mobile devices has become increasingly popular. People are less patient to wait for the important information to load on a mobile device than on desktop computers.
• Reader attention. You should bear in mind that people have other emails to read and other tasks to complete. Making an email too long may prevent them from reading it.
• Lost information. Emails that are too long may be scanned quickly and the most important information may be skipped. Consider highlighting the most valuable parts of your email to help readers easily catch the core.

8. Sending Irrelevant Emails.

Email communications not meeting the subscribers’ expectations can do more harm than good. If people subscribed to receive your product or blog updates, it would be risky to send commercial offers to them or promote cross-related products. Sending emails with content that the subscribers don’t expect can result in an increased unsubscribe and user reported spam rate for your email campaigns.

9. Not Managing the Email List Properly.

Email marketers understand the importance of handling bounce, unsubscribed emails, and complaints for their reputation. Reputable email service providers manage all of this automatically. 

However, user engagement is one of the major factors determining deliverability. The more active recipients you have on your list, the higher the engagement rate is – this is a good signal to inbox providers to send more emails to Inbox.

On the contrary, consistent sending of emails to a “dead” list increases the likelihood of the messages to be spam as they are never opened. 

With that said, tracking your recipient activity – email opens, link clicks, and conversions – helps you maintain an active subscriber base. Sending a re-engagement email to those who don’t interact is a good practice. If they don’t respond, they should be excluded from the mailing list.

10. Not Testing Your Email Deliverability.

Although there are common factors that influence email deliverability, each inbox provider has its personal criteria and scores for making email placement decisions. The same message may be evaluated and treated differently by different providers.

Testing your email deliverability on pre-send is a great opportunity to optimize the email for better Inbox placement rate and pinpoint email delivery challenges with various inbox providers.

With email testing tools like GlockApps Inbox Insight, you can run a quick email deliverability test to find out where your email lands and receive the action steps on what issues to address to improve the Inbox rate. 

Additionally, you can automate email testing and receive notifications when the test results meet a defined condition. For instance, you can be alerted if your email Inbox placement rate drops below 80%.

How to Avoid Gmail Deliverability Challenges

To avoid messages sent to Gmail addresses being deferred, blocked or filtered out as spam, make sure you comply with these sender requirements:

• Set up SPF and DKIM authentications for your sender domain; users sending 5,000 emails a day or more also need to authenticate emails with DMARC;
• Ensure your “Header From” domain aligns with either “Return-Path” domain or DKIM signature domain to pass DMARC authentication;
• Watch user complaint ratios and ensure they are below 0,3%;
• Add a one-click unsubscribe header to marketing and subscribed messages;
• Include an unsubscribe link in the message body in a visible place.

How to Avoid Yahoo Deliverability Challenges

Delivering email communications that users want to receive and filtering out those they don’t is one of Yahoo’s main goals. To assure your messages reach their target audience, consider these guidelines and requirements.

All the senders must:

• Implement SPF or DKIM authentication for outbound emails; 
• Maintain the spam reported ratio at 0,3% or less.

Bulk senders must:

• Implement SPF, DKIIM, and DMARC protocols for their emails;
• Ensure the “Header From” domain aligns with either “Return-Path” domain or DKIM signature domain to pass DMARC authentication; relaxed alignment is acceptable;
• Add a list-unsubscribe header to ensure a one-click unsubscribe process;
• Put the unsubscribe link in the message body in a clearly visible place;
• Process unsubscribed emails within 2 days.

How to Avoid Outlook Deliverability Challenges

Similar to Gmail and Yahoo, Microsoft has created a number of policies, procedures, and best practices in order to better protect its clients from unsolicited, abusive, or harmful emails. To avoid any email delivery challenges, senders who are trying to send emails to Microsoft customers should make sure they understand and comply with the sender requirements, which include but not limited to these things:

• The messages should not be sent through proxy servers and any insecure relays;
• The messages should not be sent from dynamic IP addresses;
• The messages should not include any invalid or forged headers;
• The messages must be authenticated with SPF or DKIM;
• The unsubscribe option must be put in a clearly visible place in the message body;
• The daily spam reported ratio should be 0,1% and should never exceed 0,3%.

Closing Thoughts

In an attempt to protect their users from any kind of unsolicited and harmful messages, inbox providers introduce various rules and recommendations email senders must comply with to deliver their messages to the target recipients without issues. Oftentimes, legitimate messages get caught by anti-spam filters if the sender overlooks an important configuration or practice.

Knowing the most common mistakes email marketers often make and following the sender guidelines developed by the major inbox providers, you can proactively avoid most of the email delivery challenges and ensure high deliverability for your email campaigns.