Knowledge base
1000 FAQs, 500 tutorials and explanatory videos. Here, there are only solutions!
Resolve "535 5.7.0 authentication failed" error
The mail authentication service on the servers may encounter an issue for a few brief seconds exceptionally, during unusual events on the infrastructure, for example.
If an error 535 5.7.0 authentication failed
occurs:
- Try sending the email message again, and it should go through.
If the issue persists, check the points in this guide.
Link to this FAQ: