Problem with sending Contact form via Email plugin (SMTP / starttls)

As described in this github issue (https://github.com/getgrav/grav-plugin-email/issues/23) , i too have the need for starttls as smtp encryption method (on port 587, as demanded by my hoster). But unfortunately the described fix didn't work out for me.

After updating Gravs Swiftmailer to version 5.4 via Composer and manually setting starttls as encryption method in user/config/plugins/email.yaml i still get the following error when trying to submit a contact form:

Connection could not be established with host peacock.uberspace.de [Unable to find the socket transport "starttls" - did you forget to enable it when you configured PHP? #32659]

I have no more ideas what to do, could anybody point me in the right direction (i'm running php 7.0.5 if that is of any concern)..

greets & thx from berlin

• u

Just googled this: https://forum.mailwizz.com/threads/unable-to-find-the-socket-transport-starttls.701/ something that helps you?

Thanks for your input flaviocopes ! It doesn't seem to be linked to the user credentials. I already tried 3 different e-mail accounts with different usernames & passwords. But everytime i try to submit the contact form, I get the same error message as before (Unable to find the socket transport "starttls")...
One thing i'm not sure about - when i'm choosing smtp as my engine, do i still need to set the sendmail-path in user/config/plugins/email.yaml ? Or is smtp / sendmail mutually exclusive ?

No, sendmail is a local (same server) email sending option, while SMTP uses a separate email server, to which you delegate the email sending.

ah yeah, i thought so - thanks! and btw: after a (necessary) git clone of my files, everything seems to be working fine now, in terms of starttls :)