Email SMTP/TLS in SMF

Hi, I have a serious problem. I have a SMF forum using PHP Mail suddenly stopped working but the day today, without explanation, I’ve been using for 3 weeks and never happened to me.
Probe with an external SMTP (not Gmail) server and not run nose if it is my forum, but I do not.
When using SMTP gives me these errors:

  • Could not get the response codes mail server

We didn’t change anything which could block SMTP as far as I’m aware. Are you sure your SMTP service is still working?