Why I can't connect to smtp.gmail.com:587 over ipv6?

Hello,

When I try the connection with openssl for smtpgmailcom:587 with this command:
openssl s_client -6 -debug -starttls smtp -connect smtp.gmail.com:587 -crlf -
ign_eof
I get:
421 4.7.0 Try again later, closing connection…
But if i use this command:
openssl s_client -4 -debug -starttls smtp -connect smtp.gmail.com:587 -crlf -
ign_eof
I can connect to smtpgmail:587 with no problem.

What can I do to fix this problem?

That’s a question for Google or your network administrator I am afraid. That is not Cloudflare related.