Protect yourself online
jrdixon3's profile



1 Message

Sunday, July 14th, 2019 3:23 AM

Error Code 550 on Account

I am getting this error on all e-mails sending through Outlook on the SBC Account.  I can receive messages, but cannot send. I have checked pop and smtp settings and they are correct.

Your message did not reach some or all of the intended recipients.

Subject: Test 4
Sent: 7/13/2019 8:15 PM

The following recipient(s) cannot be reached:

email account on 7/13/2019 8:15 PM
550 Request failed; Mailbox unavailable





15K Messages

5 years ago

550 Request failed; Mailbox unavailable

Did you set a reply-to in your outlook?  That would be the setting that appears in the sender (From) of email you send that the recipient sees.  If you did then is that reply-to email address verified in the webmail's send-only address for your account? 


You can't just spoof an sender address any more (I think once upon a time your could).  Now the "spoofed" sender (reply-to) address needs to be a valid email address.  The only way to specify that information is in the accounts send-only address defined in the webmail.


I'm assuming it's not been verified since the "Mailbox unavailable" error message is the result of it not being verified.  So in the webmail click the settings gear -> more settings -> mailboxes.  In the pane on the left there's section called "send-only email address" where you can add such addresses.  When you click the add you will see some info on the right you need to fill in and click the verify button which will send an email the the specified email address.  I recommend you keep the mailboxes page up.  That other email will receive an email with a message that ask you to click a set of words to acknowledge the verify.  Once verified, if you refresh the mailboxes page you should see the email address you just created in the list of send-only addresses.  Now you outlook should be able to "spoof" that address as the sender.


I think all this verification stuff is to try to discourage using att/yahoo email for spamming.

Not finding what you're looking for?
New to AT&T Community?
New to the AT&T Community? Start by visiting the Community How-To.
New to the AT&T Community?
Visit the Community How-To.