So, as the title says, i'm trying to get my mailcow to work with 2 seperate certs for mail.tekknodes.com and mail.tweeby.ca Currently it's behind a NPM (nginx proxy manager) and getting the following errors [upl-image-preview uuid=7494163f-c1a4-4d7a-94ec-22cfcdbe9c9c url=https://community.mailcow.email/assets/files/2026-09-08/1788834433-684008-image.png alt={TEXT?}] Ports are on 80 and 443 (might have to switch to 8080 and 8443) ADDITIONAL_SAN=autoconfig.*,autodiscover.* SKIP_LETS_ENCRYPT=n SKIP_HTTP_VERIFICATION=y (cause it's under a proxy of NPM) And this is all i can remember of what i have changed.

@"ETNyx"#p33177 I do have ``ADDITIONAL_SERVER_NAMES=mail.tekknodes.com,mail.tweeby.ca`` in there. Recently added that about an hour ago [upl-image-preview uuid=c4746b84-cd28-476e-a53f-36e70fcfe41a url=https://community.mailcow.email/assets/files/2026-09-08/1788849949-449407-image.png alt={TEXT?}] Is the current error im getting

> @"SkippTekk"#p33181 Ah sorry, I was hoping that mailcow would auto renew the certs It will do that, as long as you tunnel port 80 to Mailcow as well for those FQDNs. But, as @"ETNyx"#15735 wrote, you have to copy certificate and key file to your NPM proxy afterwards. ---> https://docs.mailcow.email/post_installation/reverse-proxy/r_p/

Trying to get 2 emails working with seperate SSL certs

SkippTekk

So, as the title says, i’m trying to get my mailcow to work with 2 seperate certs for mail.tekknodes.com and mail.tweeby.ca

Currently it’s behind a NPM (nginx proxy manager) and getting the following errors

Ports are on 80 and 443 (might have to switch to 8080 and 8443)

ADDITIONAL_SAN=autoconfig.,autodiscover.

SKIP_LETS_ENCRYPT=n
SKIP_HTTP_VERIFICATION=y (cause it’s under a proxy of NPM)

And this is all i can remember of what i have changed.

ETNyx

Your problem is proxy. ACME made some secret in MC (acme/ngnix). This secret must be verified from LE servers, but you are using proxy so this server is searching on your proxy and can’t find it.

In your proxy scenario most common is to have acme on your proxy and backport certs into MC

SkippTekk

ETNyx I do have ADDITIONAL_SERVER_NAMES=mail.tekknodes.com,mail.tweeby.ca in there. Recently added that about an hour ago

Is the current error im getting

ETNyx

Ok you did not understand what I wrote. Basically you are trying to make certs in wrong place. As I see it you have 3 options:
1) Get rid of proxy
2) Transfer that secret from MC to proxy
3) Make certs on proxy and backport them into MC as docs show you.

SkippTekk

ETNyx Ah sorry, I was hoping that mailcow would auto renew the certs, but can i have both certs at the same time? Not entirely sure on how that would be done cause both domains are under the same IP address.

but im very sorry for not understanding, it’s basically my first time messing with this stuff and wanting my Mails to work.

Actually… I’m looking at it, im seeing a new folder called mail.tekknodes.com and it wasn’t there at all before for the data/assets/ssl directory. would creating mail.tweeby.ca work if i throw both certs in?

DocFraggle

SkippTekk Ah sorry, I was hoping that mailcow would auto renew the certs

It will do that, as long as you tunnel port 80 to Mailcow as well for those FQDNs. But, as @ETNyx wrote, you have to copy certificate and key file to your NPM proxy afterwards.

—> https://docs.mailcow.email/post_installation/reverse-proxy/r_p/

SkippTekk

Alright awesome.

I created the folder mail.tweeby.ca added in domains with the name mail.tweeby.ca inside of it, grabbed the Certs from NPM(fullchain and key then changed em to cert.pem and key.pem) and tossed the certs into each folder inside of data/assets/ssl/{mail.tweeby.ca,mail.tekknodes.com} and my email systems are not freaking out. Thanks for the help guys!