In short, you can use a custom DNS name by CNAMEing our DNS name to your domain, but only for unencrypted FTP and sftp. If you require custom DNS for FTPs then we can provided a dedicated IP with your SSL certificate.
CNAME sfs-eu-west-1.docevent.io => sftp.mydomain.com
This will work correctly with sftp access, and with unencrypted FTP, however it will not work for FTPs.
Why does this not work for FTPs?
When using FTPs a connection is made to the server and it is upgraded to an encrypted connection using SSL. During this an invalid certificate error is shown to the client because the DNS name (docevent.io) does not match the CNAMEd address (mydomain.com).
Is there a workaround for FTPs?
1. We can add a hosted dedicated IP address to your plan for $100 a month, this will let you add a custom SSL certificate, ssh key, and dedicated instance to your account - Contact support to get this organised.
2. Use our Self-Hosted instances to host your FTP server locally in your own datacentre/cloud - https://docevent.io/self-hosted