Google tried to deliver your message, but it was rejected -535 Incorrect authent

[Dipak Bhoi]

Hello Guys,

One of our customer was facing an issue with email. He stated that, this has been working perfectly for years!  What happened now?  He was receiving an error as below.

Delivery to the following recipient failed permanently:

email.address@gmail.com

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the relay mail.domain.com by mail.domain.com. [XXX.XXX.XXX.XX].

The error that the other server returned was:
535 Incorrect authentication data (SMTP AUTH failed with the remote server)

He has configured POP3 account from gmail. In short he using gmail as a outlook.
I checked the password it is 100% correct but still giving this error. I did find for option "My server required authentication" but not such option in Google.

After investigating I found that he was able to receive email but not able to send, then the problem may be that Gmail just needs a refreshing its memory.

Follow the below steps to fix this issue.

1. Go to Settings
2. Go to Accounts and Imports
3. In the Send Mail As section, find the email address that caused the bounced reply and to the right click Edit Info.
4. Click Next Step and then Save Changes.
5. Try sending your email, it should be worked now.

That's all. You have done.

Enjoy !!