Cannot send email

[rhbvkleef]

I'm a bit confused as to why I cannot send email. This is what my log shows:

smtp::outbound::delivery: context="connect" event="failed" mx="alt4.aspmx.l.google.com" reason=I/O error: Connection timed out (os error 110)

Firewall rules allow all outbound, inbound, and forwarding, and I am able to ping `alt4.aspmx.l.google.com, both over IPv4 and IPv6. What are futher debugging steps I could take?

Edit: After enabling trace logging, no extra information is shown. Journalctl doesn't show anything interesting around the time that the email is submitted.

[rhbvkleef]

Turns out Linode is blocking outbound submission. I am now in contact with their support in an attempt to get this problem resolved.