skip to content

Troubleshoot Comcast Business email issues

Updated 7/20/2017 7:09:46 PM by Comcast Expert


This article applies to Microsoft® Hosted Exchange customers who have not yet been migrated to Microsoft® Office 365. If you are currently using Office 365, please visit Microsoft’s Set up Office 365 for business support page.

Having problems with your Comcast Business email? Learn some tricks for resolving the most common issues.

Solutions to common issues

Email client not working

If you cannot send or receive email with an email client (Microsoft® Outlook, Thunderbird, iPhone, Android, Blackberry, etc.):

  1. Step 1:

    Sign in to My Account and select Email from Manage Services.

  2. Step 2:

    Select Check my email to open webmail.

  3. Step 3:

    Create a new message and send an email to your own address. If you receive the message it confirms that you can send and receive email through Outlook Web Access. This normally means there are no issues with the email account itself.

  4. Step 4:


    Verify the server and configuration settings in the email client. Select Email from Manage Services, then select View DNS Settings. See the Configure Microsoft® Outlook to connect to your email account article for more information if you are using Outlook 2010.

Unable to send email intermittently

If you are sending a large number of emails in certain periods of time your email account may be temporarily blocked from sending email. See the Size and storage limits article for more information.

Can't send any email

Send email from a secured port to ensure outgoing emails are not blocked. See the Send email via a secured port article for more information.

Not sure which email protocol to use with an email client

See the Differences between MAPI, POP and IMAP article to learn more about the different email protocols available with your Comcast Business email. The protocol you use must be supported by both Comcast Business email and your preferred email client.

Some folders are not being synced to an email client

If your email client is not syncing a folder with your Comcast Business email, access the email or syncing settings of your email client. Look for options like "Sync Folders" or "Mail Folders to Sync."

Emails from only the past few days are being synced with an email client

If your email client is only syncing email from the past few days, access the email or syncing settings of your email client. Look for options like "Mail Days to Sync" or "Sync 'X' Days of Email."

Unable to send large attachments

There is a limit of 20 MB (megabytes) per email message, including the email content, headers, and attachment(s). You will receive an error if you attempt to send a message over 20 MB. This limit cannot be changed at this time. See the Size and storage limits article for more information.

Need to increase storage space

You can save/backup messages to your computer or another device to free space in your mailbox. Learn how to check the current available mailbox quota using Outlook 2010 and more on this topic in the Size and storage limits article.

Missing email after configuring an email client

Most email clients have an option by default to delete messages from your email's Exchange server when they are synced/downloaded to your email client. Make sure the email client is configured to leave messages on the server.

Suspicious emails/phishing

Phishing is a method used by Internet scammers who imitate real companies in email messages to entice people to share usernames, passwords, account information or credit card numbers.

Internet scammers use sophisticated lures as they "fish" for users' private information. The most common ploy is to copy the look and feel of a major web page and use that design to set up a nearly identical page that appears to be part of the company's site. See the Help protect your business from email phishing article for more information and to learn how to report suspicious emails.

If you are still having problems with your email, please call Business Customer Support at 1-800-391-3000.

Was This Article Helpful?

Rate this article on a scale of 1-5

Didn't find what you're looking for?

Related Articles

» More about Setting Up Your Business Email Account