Rackspace, the email provider we use and recommend, is dropping support for MD5 authentication starting June 26. Check your email SMTP (sending) settings to avoid trouble sending emails after this date. Please contact us or follow the instruction below to fix this issue.
CHECK YOUR SETTINGS
Ensure your Mac and iPhone mail clients do not use CRAM-MD5 authentication for SMTP (sending). We also suggest connecting via SSL when sending mail.
QUICK FIX (Temporary Workaround)
Don't have time to check? If sending breaks, then login to webmail to access and send email like normal. The webmail login can be accessed here: https://apps.rackspace.com/.