BoltMail
I clicked 'Send to existing contacts' and only half my contacts received the email. What did I do wrong?
This can happen if you have set the autoresponder to send out after a long delay.

The application will search all of your current contacts for all contacts that have been on your contact list for longer then your autoresponder is set to.

That is if your autoresponder is set to send to all users after 14 days of being subscribed and you click send to existing contacts then all of your current contacts that have been on your list for longer then 14 days will receive the email straight away.

For the rest of your contacts, they will receive this email when they reach the 14 day limit.