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Improving Email Deliverability

Get some valuable tips on how you can improve email deliverability.

Ruba

3 Jun, 2025 - Updated 9 days ago

Introduction

Getting your emails into the inbox, not the spam folder, is key to successful communication and marketing. Email deliverability depends on factors like your sender reputation, message content, domain settings, and how recipients interact with your emails. This guide offers tips and best practices to improve deliverability.

How Email Providers Detect Spam

Email services such as Gmail, Yahoo, and Exchange use various signals to decide whether your email is spam. These include:

Contact list presence: Emails from senders in the recipient’s address book are less likely to be marked as spam.
Previous spam reports: If the recipient has flagged your past messages, future ones might be filtered out.
Reputation among recipients: If many users (especially on Gmail) report your emails as spam, your sender reputation drops.
Email content: Using phrases that are commonly found in spam can negatively affect deliverability.

Tips to Improve Email Deliverability

Below are a few tips to help you improve your email deliverability.

Use double opt-in lists

The difference between double and single opt-in is that with double opt-in (also called confirmed opt-in), people get a confirmation email after entering and submitting their form with their email address. They do not get subscribed until they click the confirmation link they receive in their email. The following are the advantages of using double-opt-in lists:

Deliverability rates for the lists that use double opt-in are significantly higher compared to single opt-in lists.
Unsubscribe rates are lower than the open and click-through rates.
Double opt-in lists reduce spam complaints.

Note: You cannot use purchased or rented lists in Vtiger CRM to send emails, as it is against the CAN-SPAM ACT.

Remove subscribers who haven’t opened or clicked in six months

If people do not open or click on your emails, removing them from your list might hurt, but it will help improve the deliverability rates for the people you keep.

Send emails at the right frequency

Too many emails can reduce your subscriber list. Firing fewer emails can kill your revenue. So, what do you do to maximize deliverability? Find the right frequency by testing thoroughly.

A good benchmark is one email per week. You can try scaling up to twice weekly, as long as you have great content.
You can even drop back to once a month. But if you exceed either of these two boundaries, you might lose your audience.
Random and unusual email activity leads to lower sender scores and IP blacklisting.
Avoid sending spikes by maintaining regular email schedules.
Deliver the best for consistent outbound email scheduling.

To learn more about this, click here.

Authenticate your emails with SPF, DKIM, and DMARC

Email authentication protocols such as Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) help Internet Service Providers ensure that the email is from the company claiming to have sent it.

Authentication helps address the problems of email spoofing and phishing, ultimately leading to a reduction in the percentage of legitimate emails mistaken for spam.

Vtiger CRM supports SPF and DKIM authentication. To learn more about email authentication, click here.

Avoid using the same From and To addresses

Emails are marked as spam if both the sender’s and recipient’s email addresses are the same.

Avoid using free or personal email addresses

Instead of using your free or personal email address, such as your Gmail or Yahoo address, use your company domain-specific email address to send emails.

Personalize your email content

Personalize your emails using Vtiger CRM’s Email Templates.
Avoid using the same content in the subject and body of the email.
Avoid misspellings, using all capital letters in the email subject and the body, too many exclamations (!!!), and spammy phrases such as Buy Now, Free, Guarantee, No Obligation, etc.

Avoid copying content from other applications

When you paste content directly from other applications, such as Microsoft Word or PowerPoint, unnecessary characters are automatically added. Instead of creating templates outside and copying them, you can build them directly in Vtiger CRM.

Avoid sending graphics or images alone

Emails with a single graphic or image are sure to have delivery issues.
You should balance your emails with image and text content.
It is recommended to write at least two lines of text for every graphic.

Include text in your emails

It is a good practice to use text content along with HTML in your emails to prevent them from landing in spam. Besides, it covers you when the recipient cannot view HTML content.

Include a physical address in your email

Physical address means the mailing or postal address of your business. You can put it at the end of your emails; that is the footer.

Including a physical address in your emails demonstrates that your business is legitimate. Thus, it prevents your emails from landing in the spam folder.

To learn more about including a physical address, click here.

Avoid large attachments

In general, attachments with file types such as .jpg, .gif, .png, and .pdf are safe to send. Certain executable attachments, such as .exe, .zip, .swf, etc., must be avoided.

Pay attention to your links in emails

Spam filters check the URLs in the email. Linking to a domain that has a poor reputation leads to penalization.

Additionally, you must avoid linking to URLs that contain folders with 1-2 characters (such as domain.com/e/something/ or domain.com/es/) because some spam filters block such URLs. Also, avoid including links that utilize link shortening services, as this may cause delivery issues.

Don’t hide the unsubscribe link

Include unsubscribe links in your emails to improve deliverability rates. If the unsubscribe link is unavailable or mislocated, there is a chance that emails will be marked as spam.

Remind users to whitelist your domain

When your recipient authorizes your domain, your email will not land in the spam folder.

Analyzing Email Performance