SMTP failure leads to stuck email queue items and other issues throughout the CRM

[kale1d0code]

Issue

if SMTP fails for any reason during sending email campaigns, the item will be stuck in the email queue unless a database administrator set the in_queue field on all the affected rows to 0.

When an administrator sends a test email in the email settings page, their user session can get stuck for the duration of the execution limit for PHP.
This test shouldn't prevent any user from using the CRM user interface.

Possible Fix

The code for sending emails could be written in such a way so that it can handle issues during submission.

Steps to Reproduce the Issue

1. setup SMTP connection in SuiteCRM
2. send test email or campaign
3. fabricate SMTP connection issue (rate limit / switching the SMTP service off midway, etc)

Context

lowers the reputation of the CRM service.
raises questions about the suitability of the CRM as a marketing platform.

All versions of SuiteCRM are affected.

Version

7.14.2

What browser are you currently using?

Chrome

Browser Version

Google Chrome 129.0.6668.89

Environment Information

MariaDB 10.9.4 | 7.4.25

Operating System and Version

... Debian GNU/Linux 10 (buster)