Comcast Email Not Sending – Fix Yourself

Comcast email not sending is a common problem that many users face. In today’s fast-paced world, email has become an essential tool of communication for both personal and business purposes.

However, when emails fail to send, it can be frustrating and disrupt our daily routine.

Comcast is one of the popular email service providers, and like other providers, it has its fair share of issues.

In this blog post, we’ll discuss common reasons why Comcast isn’t sending emails and provide step-by-step instructions on how to troubleshoot and fix the problem.

Why is my Comcast email not sending?

If you are experiencing issues with sending emails through your Comcast account, there could be several reasons behind it.

Some common causes of this issue include a poor internet connection, attachment issues, syncing errors, or SMTP settings errors.

These issues can prevent your emails from being sent and can be frustrating to deal with.

Before proceeding with any troubleshooting steps, we suggest trying to send emails to multiple users without any attachments to see if the issue persists.

This can help you determine if the problem is related to attachments or if it is a more general issue with your Comcast email account.

However, If the issue persists even when sending emails without attachments, there are several steps you can take to troubleshoot and resolve the problem

How to fix Comcast not sending Emails ?

Follow below mentioned steps to fix Comcast not sending emails issue:

Disable the Spam Filter

If your emails are not being sent, it could be due to the spam filter. To fix this, sign in to your Comcast account, go to “Users and Preferences”, and click “Edit” on the spam filter option. From there, select “Disable Spam Filter” and save your changes.

Check Security Settings

If you’re using Outlook, make sure your outgoing mail server settings are set to “Auto” for security. If “Auto” is not available, you can also choose the “TLS” option.

Recreate the Account

If the issue is with the mail client or Outlook, try deleting and recreating the account. Make sure to back up any local folders before deleting the account.

Use the Correct IP Address

Comcast may block sending emails if you’re using a residential or dynamic IP address. Make sure to use as your email server and only use webmail apps with this server.

Check Your Internet Connection

Sometimes, a poor internet connection can cause email sending issues. Test your connection and restart your router or check your network settings if necessary.

Unblock Contacts

Make sure you’re not trying to send emails to blocked contacts. Check your blocked list and unblock any necessary contacts.

Clear Cookies and Cache

Excessive cookies and cache in your Comcast email account can cause sending issues. Try clearing them from your browser to fix the problem.

Also Check: How to delete Comcast Email account ?

Is Comcast receiving emails but not sending?

Comcast Emails Not Sending

One reason why Comcast may be able to receive but not send emails is due to incorrect settings. SMTP (Simple Mail Transfer Protocol) is responsible for sending emails from the user to the server.

If there is an error in entering the SMTP server and port information, the email will not be sent.

It’s important to double-check these settings to ensure that they are entered correctly.

Fix SMTP Settings

You can change the SMTP settings on Outlook or Mac Mail from the account settings.

The correct SMTP settings for Comcast are as follows:

Port: 465 or 587
Security/ Encryption: TLS (preferred), SSL/TLS, or SSL

To fix Comcast email sending issues on Outlook or Mac Mail, check the SMTP server and port settings. On Outlook, go to “File” > “Account Settings” > “Change” > “More Settings” > “Advanced”.

On Mac Mail, go to “Mail” > “Preferences” > “Accounts” > “Server Settings”. Enter the correct SMTP server and port information. This should resolve the issue.

Are Comcast emails not sending only to a particular account?

If you’re unable to send or receive emails from specific accounts, it could be due to a block or issues with the recipient’s settings. Try unblocking the contact or checking the recipient’s email settings to resolve the issue.

Unblock the account or get yours unblocked

If you had blocked someone inadvertently or for a reason, you won’t be able to send and receive emails from them until unblocked. Same is also true for the opposite user. Go to email settings to check the block list and unblock the user. Conversely, ask the designated receiver to do the same.

Check the email address

Cross check the email address you are entering in the receiver’s ID box. Spelling mistakes and typos in the email address would render the email undelivered and you will receive an email confirming the same within some time.

Ask the receiver to check his/ her settings

Other reason for receiver not receiving your emails are the recipient mail box settings. Ask him to check and enter the correct IMAP or POP (POP3) settings in the account settings.

Is Comcast not sending emails with attachment?

Comcast Email Not Sending

Have you tried sending emails without attachments? If there is no problem in sending emails without attachment, then the problem is either with the attachments’ size, internet connection, or both.

Attachment size is big

Big size attachments take longer time to send. Try compressing the attached files into smaller size. If compressing is not a feasible option for you, try dividing the attachments into multiple emails. This way, you can track which attachments are sent, and individual mails get sent in lesser time.

Internet is slow

When you are sending attachments without good internet connection, it would keep showing either queued or sending for a long time. Try running an online speed test to check the connection speed.

Also Check: How to solve Comcast hacked issue ?

Is your Comcast email not syncing with the server?

Comcast Email Not Sending

Comcast added a new security feature to Xfinity Connect email on September 16, 2020.

This feature includes a security checkbox that allows users to enable or disable access to third-party email clients such as Outlook, Mac Mail, and Thunderbird.

Enabling third-party access may put your data at risk of being breached by these clients.

However, disabling third-party access will prevent you from using Comcast email on other email clients.

When third-party access is disabled, the email will stop syncing with the cloud and won’t send or receive any emails, or it may show a generic error.

Change third party usage settings

To continue using Comcast on third party email clients such as Outlook, Outlook Express, Mac Mail, etc. turn on third party usage from the Comcast settings.

Follow these steps to send and receive emails on third party apps by turning on Comcast third party usage.

  • Firstly open Mailbox, click Gear icon, and select Settings.
  • Secondly, click on Security.
  • Thirdly, uncheck the box against Third Party Access Security.
  • Finally, you can use Comcast or Xfinity connect email on third party email clients.


In conclusion, Comcast email not sending is a common problem that can be caused by a number of factors, including incorrect SMTP settings, poor Internet connection, or blocked contacts.

This blog post provides detailed instructions on how to troubleshoot and fix the problem, including how to disable spam filters, check security settings, and clear cookies and cache.

By following these steps, you will be able to resolve any issues with sending email through your Comcast account and start communicating smoothly.

Remember to double check your SMTP settings and make sure they are entered correctly to avoid any further issues

Frequently Asked Question’s (FAQ’s)

Why is Outlook express not sending email via Comcast?

Outlook express not sending Comcast email because of Third party Access settings. Change third party access settings from Comcast Mail Box > Settings > Security > Third Party Access Security.

What is the outgoing mail server for Comcast

The Outgoing mail server for Comcast is

How do I fix an SMTP error?

You can fix SMTP error by re-adding the email account into the email client with right SMTP settings.

Is Comcast email POP or IMAP?

You can use both POP3 and IMAP on Comcast email. However, the company recommends using IMAP so that you can easily read emails on multiple devices.

Content Writer

Smith Ron, the writer at Assistme360. He has extensive experience in crafting straightforward, step-by-step guides for technical issues. His broad knowledge ensures accurate solutions. Kindly spare a moment to drop a comment down and express your opinions. Your feedback can be valuable in assisting others who may come across similar problems.

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