Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

Avatar for Username

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

Natao arisiva ity resaka mitohy ity. Mametraha fanontaniana azafady raha mila fanampiana.

STARTTLS is required to send

  • 1 valiny
  • 1 manana an'ity olana ity
  • 7 views
  • Valiny farany nomen'i sfhowes

firefox1400
firefox1400
more options

I get this message when trying to send an email from my linux laptop:

An error occurred while sending mail. The mail server responded: 451 5.7.3 STARTTLS is required to send mail [CO2PR04CA0178.namprd04.prod.outlook.com]. Please verify that your email address is correct in your account settings and try again.

Background: My email server was recently migrated to office365. Many features worked okay until 24 hours later. The email support person (from godaddy) walked me through updating the incoming and outgoing server addresses, but had no idea what to make of this error message.

Can anyone help walk me through whats going on and how to fix it? Thanks!

I get this message when trying to send an email from my linux laptop: An error occurred while sending mail. The mail server responded: 451 5.7.3 STARTTLS is required to send mail [CO2PR04CA0178.namprd04.prod.outlook.com]. Please verify that your email address is correct in your account settings and try again. Background: My email server was recently migrated to office365. Many features worked okay until 24 hours later. The email support person (from godaddy) walked me through updating the incoming and outgoing server addresses, but had no idea what to make of this error message. Can anyone help walk me through whats going on and how to fix it? Thanks!

All Replies (1)

sfhowes
sfhowes
  • Top 10 Contributor
more options

What's the connection security for the outgoing server? It should be STARTTLS on port 587.