Most of the time, outbound WebDAV connection issues are caused by one of the following things:

Most common issues are related to Firewalls or other restrictions on the remote server that require an IP address to be whitelisted

It is possible that the outbound server doesn't actually accept WebDAV

Should also double check whether you are using the wrong port, hostname, or other settings

Please check with your counterparty about any IP Address restrictions or whitelisting that may be in place. If any is in place, please read and follow the below instructions carefully:

IP Addresses Used For Connection

If you have a Custom Domain installed on your site, that means Files.com has provisioned two dedicated IP addresses for your site and it will use them by default for outbound connections to the remote server. Provide these 2 IP addresses to your counterparties and ask them to whitelist them in any applicable firewall.

If you do not have a Custom Domain installed on your site, you do not have Dedicated IP Addresses provisioned for your site and Files.com will use its entire pool of IP addresses for connecting outbound to the remote server. If your counterparties maintain an IP Address whitelist, you will need to have them whitelist all of the IPs on this list.

Customers often ask for Dedicated IP addresses as a way to avoid having to ask their counterparty to whitelist a huge list of IP addresses.

We are able to offer that for Remote Server connection purposes via somewhat of a backdoor method, which is adding a Custom Domain to your site. Having a custom domain provides a justification for the dedicated IP address.

Files.com automatically provisions a pair of dedicated IP addresses for every site that has a custom domain enabled. We do that because FTP, unlike HTTP, requires that every custom domain be hosted on a dedicated IP address in order to have a custom SSL Certificate that matches the domain.

This means that if you have users who restrict outbound access via a firewall, they will only need to whitelist your two dedicated IP addresses. rather than having to whitelist our entire published list of IP addresses (see above).

Custom domains and, therefore, dedicated IPs are only available on the Power and Premier plans.

Dedicated IPs, once provisioned, are used for both inbound connections to your site via your custom domain, as well as outbound connections from Files.com to certain applicable Remote Servers that are used for Remote Server Sync and Remote Server Mount.

By default, Files.com will use your dedicated IP addresses for outbound connections to FTP, SFTP, WebDAV, and S3 Compatible remote servers. However, you can disable the use of your dedicated IP in these circumstances if you need to. (You might do that if your counterparty has already whitelisted the main Files.com IP range, for example.)