Using a mailing list software package instead of an address book contact list might work better for you. Some are free, some cost money, but one of the standard features is an automatic unsubscribe mechanism for email address that are invalid or bounce several times in a row. How are you storing your list of addresses now and how are you sending the email to them? Who provides you with your email account and SMTP server? It's unlikely that a residential ISP has an option to help you with this but it's possible. Do you know what limits your ISP has for the number of email you can send in a day and/or the number of recipients that are allowed per email?
I copy and paste a list emails to an excel sheet. These emails come from people who are trying our product for the first time. Alot of times; people don't want you to email them, so they put in incomplete email addresses. I'm trying to find a way of deleting these either when I copy/paste or am trying to send through my outllook.
We have an admin website that I simply copy from. I then paste this list into microsoft excel and copy them to my outlook. When I try to send from my outlook; it tries to give suggestions for the incomplete email addresses which is very time consuming to have to go back in and find each incomplete email address. Sometimes they don't even have the @ sign in them.
Yes, I stand by my previous recommendation then that your admin page should have some better code in it, or better yet the form collecting the information could have some smarter programming. Do you have a web person who can make the update? There is an example of the php linked to in my above post.