Trouble sending emails

I have just setup SMTP using a SendGrid account.
This account is working fine from the VM running Buddy. I can send emails to different recipients using basic mail and postfix.
Buddy invitation emails are not arriving and I would like to troubleshoot this. Where do I find the log files if any? What other tests can I use?

Thanks in advance.

Hi Jose,

In the .buddy/app/data/backend/logs/application-server/ folder, there should be files webservice.log, email.log, and email-failures.log – you may look for some hints there.