Emails wont send in WHMCS - Email Sending Failed: invalid_grant (Subject: WHMCS Cron Job Activity)

[frynge]

I'm getting errors in my WHMCS, when it sends out automatic emails.

 

I'm using GMAIL as a mailer and had to set it up and it was working fine.  But lately it will not send out emails and they are backing up! I need some help

The errors I'm getting are:

Email Sending Failed - Email Sending Failed: invalid_grant (Subject: Invoice Payment Reminder)
Email Sending Failed - Email Sending Failed: invalid_grant (Subject: Invoice Payment Reminder)
Email Sending Failed - Email Sending Failed: invalid_grant (Subject: Invoice Payment Reminder)   
Admin Email Notification Sending Failed - Mailer Exception - Email Sending Failed: invalid_grant (Subject: WHMCS Domain Synchronisation Cron Report)
Admin Email Notification Sending Failed - Mailer Exception - Email Sending Failed: invalid_grant (Subject: WHMCS Domain Synchronisation Cron Report)

 

"Invalid_grant"

[zetaone]

We are running into the exact issue.

Wish someone from the WHMCS dev team could pitch in with a possible solution as there is no error output to work with.

 

 

[Damo]

The error suggests an authentication problem with gmail. Try checking the configuration of your mail settings, and possibly set them up again. 
 

We don't use gmail here so not sure if it uses app passwords, oath or another method. 

[M.Ammar]

After checking your Cron logs it seems that the error you are getting is due to your Gmail SMTP are Invalid, please reconfirm your Gmail SMTP settings in order to resolve the issue.

[zetaone]

More often than not and it still might need some tweaking by the WHMCS dev team to behave as might be useful, the issue is misconfiguration on the user's part.

For us, it was just an accidental space in the URL that triggered the issue. Once corrected, the issue went away.