Verify email address

If you use a large distribution list over time some of the email addresses may become invalid due to a user losing their email account. Some SMTP servers refuse to send a message until they verify all of the recipients, and return a error message that doesn't identify the bad email addresses. For example, "An error occurred while sending mail. The mail server responded: MAILBOX NOT FOUND. Please check the message receipts and try again."

One way to avoid this problem is to install the ThunderPlunger extension. You could right click on the address book that has the distribution list and choose "Verify Email Addresses". It will display a list box that identifies whether each email address is valid, and gives you the option to select which invalid email addresses it should remove. It doesn't give you the option to edit the contact for a bad email address, you need to manually make a list of the bad email addresses it displays and press cancel when its done verifying the email addresses if you want to do that. [1] More information about it is available at the projects web site.

Keep in mind that its not always possible to verify a email address by a network check, sometimes you have to send a message and get it bounced. For example, if a mail server is split into multiple components the SMTP server can reject mail to unknown users but might not know how to explicitly check for the existence of a particular user. [2]