Allow setting the $self variable in SmtpMailer manually

[janbuchar]

• bug report? no
• feature request? yes
• version: 2.4.0

Description

It would be great if we could set the $self variable (https://github.com/nette/mail/blob/master/src/Mail/SmtpMailer.php#L133) manually (e.g using config parameters) - if it's set to localhost, some mail servers consider our mails spam. Our use case is sending e-mails from the CLI, where it makes no sense to set the HTTP_HOST variable used by SmtpMailer.

[dg]

Can you send pull request?

[janbuchar]

Of course, as soon as I think of a meaningful name for the option.