Update firststeps-ssl.md

docs/firststeps-ssl.md

@@ -31,7 +31,7 @@ A wildcard name like `autoconfig.*` will try to obtain a autoconfig.DOMAIN_NAME
 
 Run `docker-compose up -d` to recreate affected containers automatically.
 
-## Validation errors and how to skip validation
+### Validation errors and how to skip validation
 
 You can skip the **IP verification** by setting `SKIP_IP_CHECK=y` in mailcow.conf (no quotes). Be warned that a misconfiguration will get you ratelimited by Let's Encrypt! This is primarily useful for multi-IP setups where the IP check would return the incorrect source IP. Due to using dynamic IPs for acme-mailcow, source NAT is not consistent over restarts.
 
@@ -41,11 +41,16 @@ You can also skip this validation method by setting `SKIP_HTTP_VERIFICATION=y` i
 
 If you changed a SKIP_* parameter, run `docker-compose up -d` to apply your changes.
 
-## Disable Let's Encrypt function
+### Disable Let's Encrypt
+#### Disable Let's Encrypt completely
 
 Set `SKIP_LETS_ENCRYPT=y` in "mailcow.conf" and recreate "acme-mailcow" by running `docker-compose up -d`.
 
-## How to use your own ceritficate
+#### Skip all names but ${MAILCOW_HOSTNAME}
+
+Add `ONLY_MAILCOW_HOSTNAME=y` to "mailcow.conf" and recreate "acme-mailcow" by running `docker-compose up -d`.
+
+### How to use your own ceritficate
 
 Make sure you disable mailcows internal LE client (see above).
 
@@ -59,7 +64,7 @@ docker exec $(docker ps -qaf name=nginx-mailcow) nginx -s reload
 docker exec $(docker ps -qaf name=dovecot-mailcow) dovecot reload
 ```
 
-## Check your configuration
+### Check your configuration
 
 Run `docker-compose logs acme-mailcow` to find out why a validation fails.