Formbuilder not sending mails via SMTP

[musicscore]

Hi There.
Because my hoster is blocking php mail (and sendmail) due to security concerns I want to use smtp for sending mails from a form that is available of multiple customers websites.
So I configured the mailsetting in cmsms to use smtp and send a test mail from the mailsetting screen (see attachment)
The mails are send as expected. So I think SMTP is configured correctly in CMSMS.

But when I use the form the form is not sending the e-mail. Looks like the form is not using smtp.
Is there something I have to configure to make this work.

Testing on a private host where php mail is enabled, the mail is send correcly but on my production environment, php mail is disabled as mentioned before and I only can use SMTP.

Please advise.

[DIGI3]

Formbuilder uses the CMSMS settings, so something else is going on. Usually it happens if the "from" address in the FB disposition isn't the same as configured in CMSMS, but you may also have to check your SMTP logs to see if it's something else.

[musicscore]

Problem found.

In the form I created I have a field "From address" with contains te e-mailaddress of the user that sends the form.
When this field is set to "from address" the smtp server willl not accept the mail as legal because the from address (in the header of the mail) is not the same as the on the smtp server logged-in user.
So I set that field to "Return address" and then everything works as expected.
The mail is then send from the same user as I set in the Mail service settings in CMSMS.

It is very important to set the send user the same as the user thats logon to the SMTP server.

Thanks for the tip DIGI3. That made me find the solution.