Override SMTP Credential plugin seems to work with one identity only

[xmzl]

The Override SMTP Credential plugin seems to work correctly with accounts that have one identity. However, with multi-identity accounts it always returns the error 'Authentication failed', whatever identity is used.
Debian 11, Linux 4.19.0-17-amd64 on x86_64

To Reproduce
Steps to reproduce the behavior:
Setup of sending via an external SMTP
Adding one or more identities to an account
Route all outgoing mail with the SMTP Override plugin

Expected behavior
Authentication failed message

[the-djmaze]

Depends how you've setup the Override users part.

[xmzl]

If you mean the configuration in the Administrator panel, the one in the screenshot is the current configuration. I intentionally deleted SMTP User to take the screenshot. The exact same configuration worked in Rainloop

[the-djmaze]

With the above change you can log what is working and what fails.
However, since the log is DEBUG you must modify application.ini to enable logging and the log level at 7

[the-djmaze]

Looking at your log the important part is:

[2022-06-09 10:18:38.996][08ec5960] SMTP[NOTE]: Start connection to "ssl://authsmtp.securemail.pro:465"
[2022-06-09 10:18:39.075][08ec5960] SMTP[NOTE]: Connect (success)
[2022-06-09 10:18:39.116][08ec5960] SMTP[DATA]: > AUTH LOGIN\r\n
[2022-06-09 10:18:39.137][08ec5960] SMTP[DATA]: < 334 VXNlcm5hbWU6\r\n
[2022-06-09 10:18:39.137][08ec5960] SMTP[DATA]: > Base64String=\r\n 

Where the Base64String=\r\n is something like [email protected]
But the question is: which password is used for that username?
To find that out you must edit application.ini and set:

hide_passwords = Off

NOTE:

• never post the log
• only do this while testing
• remove the log afterwards
• set back to On

[the-djmaze]

Added a new plugin named "Login Override" for next v2.25.2
It has two mapping options: IMAP and SMTP

Each line in the field will be like [email protected]:user1:password1

• [email protected] the currently used email address to login with
• user1 when set it will be used for IMAP or SMTP login
• password1 when set it will be used for IMAP or SMTP login

[email protected]::password1 will use the default login name
[email protected]:user1: will use the default login password

Why v2.25.2? Well i've modified the config options system to allow storing encrypted values.
As the mapping contains sensitive login credentials it will be stored encrypted.