Spamhouse blacklist

[alexm]

Hi

I have issues with email delivery. I only use outgoing emails.

It stopped to work few days ago with errors like (real emails obfuscated):

{
"ts": 1703054108321,
"type": "deferred",
"direction": "outbound",
"uuid": "92161D3E-B024-...-B4AB-87FC379D7F7C.1.1",
"messageId": "5c5a3b3c-db5c-3029...@email.com",
"mailFrom": "app@email.com",
"spamStatus": null,
"mailbox": null,
"quotaPercent": null,
"rcptTo": [
"my@email.com"
],
"message": "Tried all MXs",
"delay": 1024
}

When I check email status in Cloudron admin I see that according to it, server IP (we hosted on OVH) is in Spamhous black list.

I went to Spamhous website, appears that it isn't black list for spam, but kind of overuse of open resolver, here is the full article

https://www.spamhaus.com/product/help-for-spamhaus-public-mirror-users/

I suspect that other users hosted on OVH may be affected.

What is the best way to deal with it?

Having email not functioning isn't good, no password recovery, invites etc.

[jdaviescoates]

@alexm said in Spamhouse blacklist:

What is the best way to deal with it?

I'd try contacting OVH support and seeing if they can get it resolved at their end.

[alexm]

I am kind of struggle to understand is it the problem of OVH or the way Cloudron uses this Spamhous open relays?

[girish]

@alexm said in Spamhouse blacklist:

I am kind of struggle to understand is it the problem of OVH or the way Cloudron uses this Spamhous open relays?

VPS providers have a block of IP addresses and they cycle these IP addresses across their customers as VMs keep getting created and destroyed. This means that your IP was used by someone else previously and maybe they sent a lot of spam (an unfortunately common situation). When this happens, spam watchlists like SpamHaus place the IP address in their email blocklist . In some cases, people will wholesale block the entire VPS provider IP address range since the VPS provider is not responding to spam appropriately. There is a lot of unknowns here since all this handling is not "transparent" - an email receiver can use all sorts of blocklist providers and unknown criteria to determine if your email is "spam" or not. They might even block emails by domain name etc.

Your best bet for reliable email is to sign up and use a relay - https://docs.cloudron.io/email/#relay-outbound-mails . If you don't want to use a relay, you have to be "patient" to give your IP and domain a good reputation . You have to also get your IP/domain whitelisted from the various email block list providers. Most of the email blocklist providers have an online form that you can fill up to prove your reputation.