Webform doesn't send email using MIME Mail

Question

My webform forms doesn't send the email if I set Site-wide default MailSystemInterface class to MimeMailSystem.

It works fine if I set Site-wide default MailSystemInterface class to DefaultMailSystem

Take a look at my captures:

I was working fine until yesterday, then all the sudden this problem is happening.

How can I trace this?

Answer 1

I had a similar, slightly different, issue after updating from webform version 7.x.3.25 to 7.x.3.27

WORKED FOR ME:

Upgrade to webform 7.x.4-branch