If you are trying to manually setup an autodiscover record for a mail service then the format is as follows:
Record NameTypePriorityValue
| _autodiscover._tcp | SRV | 5 | 0 443 mailserver.example.com |
| [RECORD] | [RECORD TYPE] | [priority] | [weight] [port] [target] |
If your DNS provider doesnt have SRV records available to you – it might theoretically be possible to use a TXT record with the priority, port and target value in it. I cannot find if that will work or not.
