DPMMA-3031 Configurable email address length limit to prevent delivery issues

[patrykgruszka]

Q	A
Bug fix? (use the a.b branch)	🟢
New feature/enhancement? (use the a.x branch)	🔴
Deprecations?	🔴
BC breaks? (use the c.x branch)	🔴
Automated tests included?	🟢
Related user documentation PR URL	mautic/user-documentation#350
Related developer documentation PR URL	mautic/developer-documentation-new#...
Issue(s) addressed	Fixes #7732, https://forum.mautic.org/t/logs-are-full-of-mail-error/12245

Description

This PR introduces a new configuration option in the Email settings to set a maximum length limit for email addresses (including display names). This feature helps prevent delivery issues with email servers that have strict length restrictions.

Changes:

• Added a new configuration field mailer_address_length_limit in the Email settings
• Implemented logic in the MailHelper class to truncate long email addresses to only the email part (without display name) when they exceed the configured limit

---

📋 Steps to test this PR:

1. Open this PR on Gitpod or pull down for testing locally (see docs on testing PRs here)
2. Go to the Mautic configuration page and navigate to the Email Settings section
3. Locate the new "Email Address Length Limit" field
4. Set a value (e.g., 100) and save the configuration
5. Create a new email with a recipient that has a very long display name
6. Send a test email and verify that the recipient address is truncated correctly if it exceeds the set limit

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 63.49%. Comparing base (47d2e86) to head (393a905).
Report is 5 commits behind head on 5.2.

Additional details and impacted files

@@            Coverage Diff            @@
##                5.2   #14577   +/-   ##
=========================================
  Coverage     63.49%   63.49%           
- Complexity    34637    34638    +1     
=========================================
  Files          2273     2273           
  Lines        103613   103621    +8     
=========================================
+ Hits          65784    65792    +8     
  Misses        37829    37829           

Files with missing lines	Coverage Δ
app/bundles/EmailBundle/Form/Type/ConfigType.php	100.00% <100.00%> (ø)
app/bundles/EmailBundle/Helper/MailHelper.php	78.40% <100.00%> (+0.16%)	⬆️

[mautibot]

This pull request has been mentioned on Mautic Forums. There might be relevant details there:

https://forum.mautic.org/t/logs-are-full-of-mail-error/12245/3

[kuzmany]

Code is good to me.
Just thinking If shouldn't be also part of EmailValidator https://github.com/mautic/mautic/blob/189dadcfb697e3985ef894ec9d66b6c0a3147fcb/app/bundles/EmailBundle/Helper/EmailValidator.php

But could be part of another PR.

👍

[escopecz]

Since this doesn't prevent email sending but only decides whether to add the contact name to the email address or not based on the length of the email address + name. I don't see an issue with this.

The provided tests shows this works as described. But I leave this open for additional manual test.

[escopecz]

One thing is unclear. This looks more like an enhancement than a bug fix. Shouldn't we target 6.x instead of 5.2?

[patrykgruszka]

@escopecz while this is technically an enhancement, it addresses an issue that prevents emails from being sent to a specific group of contacts. That's why I choose 5.2, but if you believe that version 6.x would be more appropriate, I can rebase it.

[escopecz]

I think technically this doesn't solve a bug in Mautic but in an integration. But that's politics. It might help fix an issue that Mautic users are having. Let's leave it in 5.2.