Relationships between default from email, from address in the campaing, username in the SMTP settings

[cbertelli]

I thought that the From address in the campaigns overrides Default 'from' email in Settings and use the corresponding SMTP settings. This does not seem to happen, at least in the version I'm using (v4.1.0).
This is somehow related to #2172 but it may be a topic in the documentation I did not understand (I couldn't find satisfactory informations about it, sorry).
What I'm doing now is changing the default sender before changing the from address in the campaign, then I disable all SMTPs settings except the server corresponding to the campaign 'from' email. This behaviour seems superstitious, but when I tried the reasonable settings, it did not work.
I would think that, despite choosing a default email, when I putting a from address in the campaign, Listmonk would choose the SMTP with the corresponding username. Maybe there are use cases where this behaviour is wrong, but I wonder if they exist.
By the way, when I test the connection in the Settings->SMTP panel, the default sender gets in and I cannot test without modifying the Default sender.

[knadh]

Whatever is entered in the From field on the campaign form is the address that is used. By default, it populates the default value set in Settings -> General, which is there as a shortcut to save time.

If your e-mails aren't going with the address in the From field on the campaign page, then your SMTP server may somehow be rewriting it.