Knowledgebase Receiving Delivery Failures for Messages You Didn’t Send If you receive delivery failure messages for emails you did not send, there are two common causes. Your mailbox may have been compromised, or… Read article
Knowledgebase 503 Valid RCPT Command Must Precede DATA This error normally appears when your email program tries to send mail without authenticating correctly. The mail server is rejecting the message because it… Read article
Knowledgebase Mail Server Hostnames The mail server hostname is the server address your email program uses to connect to your mailbox. Recommended Mail Server Hostname For most mail… Read article
