WebSphere7 tip - Using GMail
By default, Portal deployed on WebSphere 7 will not be able to send any email to Gmail, even if the portal is configured correctly (pop.gmail.com:995; smtp.gmail.com:465; secure network connection). The reason is that WebSphere doesn't allow usage of untrusted certificates and signers.
Domain smtp.gmail.com has a certificate issued by Equifax Secure Certificate Authority. So, the solution is simple, we need to add this certificate to the trust ones.
1) Download certificate:
wget --no-check-certificate https://www.geotrust.com/resources/root_certificates/certificates/Equifax_Secure_Certificate_Authority.cer
2) Add downloaded certificate in WS7 admin:
SSL certificate and key management > Manage endpoint security configurations > liferayNode01 > Key stores and certificates > NodeDefaultTrustStore > Signer certificates