Do messages you send to subscribe to mailing lists come bouncing back? The receiving computer may be rejecting messages that include anything beyond mailing list commands like subscribe and unsubscribe. The culprit may be your e-mail signature, so delete it before you send the message. If your mail software adds signatures automatically ù in other words, if you don't see them when you write your notes ù try sending the message via a different client, or disable your signature temporarily.