Cannot use custom SMTP for messaging (SMTP connect() failed)

Hey there!

I'm on Appwrite Self-hosted 1.9.0.

I've never used the messaging feature before, always sent emails through functions or a custom backend, but I've decided to give it a go, since it aligns with the rest of the codebase.

However, when adding a custom SMTP provider in the messaging section and trying to send an email, I always get a failed delivery with the following message:

Failed sending to target xxx@gmail.com with error: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

The SMTP configuration is exactly the same as set in .env and in the project settings, I've checked 9 times. When sending password recovery emails or other emails from the Auth section, everything works as intended using that same SMTP provider. I've also tried changing ports (587, 465, 25) with and without TLS/SSL, and enabling and disabling "Auto TLS" in the messaging provider, to no avail.

When looking at the logs at the containers appwrite-worker-messaging and appwrite-worker-mails, nothing shows up, zero logs.

This has been reported before here https://discord.com/channels/564160730845151244/1217058432457113710 But although it was fixed, it doesn't seem to work.

Can I do something else to troubleshoot this? Since there are no logs, I'm not sure where the problem might be.