SMTP Settings for Sending Through Gmail


New Member
I've tried to follow your directions for setting up for using GMAIL. I don't understand why it's not working. I keep getting an 5.7.8 authentication error while communicating with the server. I feel quite confident that my user name and pass-code is accurate because I successfully login to Gmail everyday. I've tried applying "login" and "plain" under ESMTP authentication. Unsuccessful!

Might "DKIM" have anything to do with it?
What am I missing here?

GMAIL SMTP Settings.png


New Member
I have the same problem. I'm working with two G Suite accounts. One address works fine. The second one, with the same server settings and a known-to-be valid email address and password, gets this 5.7.8 error. (When I use Firefox to log into the account, the credentials work fine.) I tried doing a Save As from a file using the address that works, changing the email and password, but no love. I tried changing the password in my admin dashboard, and updating it in MBM, but I get the same error. I've tried copy/pasting the password, and I've tried manually inputting it. Any suggestions for what to try next?


New Member
In G Suite admin, I allowed users to have control of that setting. I then went to the account that I'm trying to send on behalf of and turned it ON.
Unfortunately, same error. Waited a couple of hours in case of latency. Same error.


New Member
Enabling access for "less secure apps" means that the client/app doesn't use OAuth 2.0 . OAuth 2.0 is the industry-standard protocol for authorization. When you sign in with OAuth 2.0, you sign in to Google's system directly. In OAuth 2.0 , you authenticate directly to Gmail with your credentials and authorize an app to do certain things. The third-party app only sees an authorization token provided by Google as proof that you authenticated correctly and agreed to authorize that app.


Staff member
Yes, e-mail client software doesn't use OAuth 2.0 but LOGIN over TLSv1.2. Gmail server supports those schemes:
and believe me TLSv1.2 is quite secure so 'Less-Secure App' means apps not controlled by Gmail, that's all. They want you to use there Webmail system.

Subscribe to our Youtube Channel and watch our tutorials!
Follow on Facebook | Linkedin | Twitter | YouTube
and keep up-to-date with the latest Max Programming updates!


New Member
MBM 8.7.2
Mac OS 10.15.4
After months of working fine using MBM to send via G Suite accounts, I'm now getting a time out while: "Connecting to Port:587"
It tries 5 times and quits.
Any suggestions?