Error Sending Email. Please contact your administrator for assistance...?

Set up SuitCRM 7.10 beta (yesterday is was 7.9.7 but had the same error).
I have a working incoming mail and a outgoing mail. In the admin panel i can sent a test mail successfull.
But when is want to compose a mail (from menu: support ==> mails) i get an error (Error Sending Email. Please contact your administrator for assistance.). I even added an extra outgoing SMTPaccount form the config button in my profile (not the system account).
My logfile shows: Nov 23 20:16:32 2017 [7259][1][SECURITY] User xxxxxx attempted to send an email using incorrect email account settings in which they do not have access to.

I was glad that 7.10 solved another problem with archived mail (not showing the right body text form archived mail) but not possible to send is a showstopper for me :slight_smile:

If you are sure that your user is not trying to send email with an account that belongs to another user, you might want to check (or re-do) your email account configuration, something might have got corrupted.

Normally I just go and check in the database, using phpMyAdmin, the table outbound_accounts. There it’s easy to see which accounts you have, and assigned to which users.

There are also SMTP debugging tips here that might help understand what’s going on under the hood:

That will put email passwords in your logs, so be careful with that.

Thanks PGR!
There was only one user active because it is a proof of concept installation. I decided to make a clean install with the LTS version. I configured there my incoming and outgoing mail account and now it works.
Don’t know what caused the problem.