At some time in your career you will switch to a new e-mail service provider (ESP). Switching ESP’s can have a major impact on your deliverability. Historically, switching was easy and painless, but in today’s delivery environment it can be quite a challenge to show the ISP’s that you are not a spammer.
When switching ESP’s, you will get a new IP address and you will need to bring your new IP address up to speed slowly, rather than sending full throttle right away. The reason why, spammers usually jump to a new IP address when they get blocked from an old one, then blast out e-mail right away. ISPs get suspicious when they see email volumes spike from unknown IP addresses, so they block first based on sudden volume spikes and ask questions later. This procedure is called throttling.
To get the best results, ramp up your sends slowly, sending a limited number (5,000/day) of messages to small subsets of the best addresses on your mailing list. As you begin to build your reputation, you can start building your volume, but always while keeping an eye on your deliverability reports and spam-complaint rates. If you ramp up your sends with a new ESP, it shouldn’t take more than a week or two to have your reputation established with the ISP’s. Good sending….
