Hi, there. Welcome to Track123.
If your domain verification failed, it may be because some DNS providers automatically append your domain name.
For example, mx._domainkey.bytrack123.co is created by combining mx._domainkey with your domain (bytrack123.co).
In this case, you simply need to remove the domain name when entering the DNS record.
First record (TXT): Enter only mx._domainkey (omit the .).
Second record (TXT): Enter just track123-mail(omit the .).
Third record (CNAME): Replace email.track123... with email.track123-mail (omit the .).
If the new hostname already exists in your Domain settings, please contact us.