This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Unable to send emails Comcast business

  • 2 replies
  • 4 have this problem
  • 1 view
  • Last reply by Chas67

more options

Since Comcast forced migration to office 365, I am able to receive emails with Thunderbird but I'm not able to send. The outgoing server is set to smtp.office365.com per Comcast instructions. This is a business account. However, this will not work with TB and I am wondering if there is a fix for this issue? I am able to send from the office 365/Comcast website, but I would like to continue to use TB.

Since Comcast forced migration to office 365, I am able to receive emails with Thunderbird but I'm not able to send. The outgoing server is set to smtp.office365.com per Comcast instructions. This is a business account. However, this will not work with TB and I am wondering if there is a fix for this issue? I am able to send from the office 365/Comcast website, but I would like to continue to use TB.

Chosen solution

I use these settings:

     INCOMING: account46, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

And yes, it is an Office 365 account.

Read this answer in context 👍 0

All Replies (2)

more options

Chosen Solution

I use these settings:

     INCOMING: account46, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

And yes, it is an Office 365 account.

more options

Thanks for the suggestion, Zenos. Seems to be working now. I can say that the Cloud Solutions team at Comcast was not very helpful.