Avast is blocking Atlassian jira outgoing emails

Hi!
I recently installed AVAST for Business, but it is blocking the emails which Atlassian jira send, unless if I disable the following Avast options:
Active Protection » Email Shield » Check received emails (POP3,IMAP4)
Active Protection » Email Shield » Check sent emails (SMTP)
With these options enabled I get the following error:

An error has occurred with sending the test email:
com.atlassian.mail.MailException: javax.mail.MessagingException: Could not connect to SMTP host: [hotname], port: [port];
nested exception is:
javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at com.atlassian.mail.server.impl.SMTPMailServerImpl.sendWithMessageId(SMTPMailServerImpl.java:201)

Any ideia why this error is hapenning and how to avoid it?
Thanks

Looks like a issue with the encryption of the email outbound? Does Jira send email through Outlook or other email client or do you setup your SMTP server in the program and it relays out directly?