Client was not authenticated to send anonymous mail

Please check out Client was not authenticated to send anonymous mail through Office 365 for the latest information on this topic.

Suddenly, i got this message while testing through OUTLOOK 2007 :

"Send test e-mail message: Cannot send the message. Verify the e-mail address in your account properties.  The server responded: 530 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM [MA1PR01CA0099.INDPRD01.PROD.OUTLOOK.COM]"

Everything is working fine earlier and no changes were made on our side and also have configured my DNS txt record, changed login password but still nothing happens.

I would appreciate if someone could help me on this.



Hi Taranvir,


This indicates that you are connecting to the SMTP client submission endpoint (, which can't be used for direct send. For direct send, use the MX endpoint for your Office 365 tenant, which ends with "" So, please let your admin check the MX record. Moreover, please check if the SMTP port is 25/TLS.


Does the "have configured my DNS txt record" means the SPF record? if so, please check if the SPF record  looks similar to this: v=spf1 [static IP address] include: ~all, where the " [static IP address]" means optional.


Moreover, you can try the following suggestions to check if there is any improvement:

  1. Remove the account and add it again to check the issue.
  2. Try using another same tenant account to check the issue.
  3. If possible, please update the Outlook 2007 to 2016 for the best assistance.






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Question Info

Last updated August 14, 2020 Views 163,795 Applies to: