Verify/change mail service DNS records and their data columns. We recommend you having two (primary and backup) "A" and "MX" records for each mail service listening different IP addresses. However, if you don't have available server IP addresss or your mail server will listening only one IP address it doesn't make any sense to have an additional "mail2" A and MX records, so they can be deleted from the list.
SPF ("TXT" record of a special format) is also required for any trustworthy mail service.
You may also want to change (or add) those DNS records to allow you customers accessing mail server using "pop.mydomain.com" and "smtp.mydomain.com".