I've been troubleshooting this for nearly 24 hours now. Was working fine until an update happened. Postfix file hasn't changed (set to my router's ip AKA default gateway). I tried changing it to 22.214.171.124 but nothing changed, so I reverted it back. I am able to ping outside of the network with zero issues, as well as within the network. Checked if it was the smtp server, but it all checks out fine. Really scratching my head about this. Internet is perfectly stable.
Here are my settings (without giving my personal email).
Any further info needed let me know.