We are currently experiencing a webmail login issue for domains hosted on the Squid 19 server. This issue does not appear to affect users accessing email via an external email program.
We will post more information as it becomes available.
UPDATE: 7:30am PST This issue has been corrected. If you are still experiencing problems, please try clearing your browser cache first and try again. If you still cannot login to your webmail, please create a support ticket so that we can troubleshoot any existing problems with this.