- Created and uploaded a "permission-based" list where contacts have expressly given their permission to receive your mail. This is NOT everyone in your Outlook contact list!
- Provided "email authentication" which identifies you as the real sender from your ESP. This is done in your settings.
You'll also find emails that didn't quite make it where they were supposed to go. An email bounces for several reasons. It can be blocked by a server, your recipients could be on vacation (lucky them), or some glitch occurred during transmission.
Any "non-existent" addresses should be reviewed for obvious typos (extra spaces, .com vs. .net, etc.). Remove these. Repeated attempts to email non-existent addresses will hurt your deliverability rates. They remain a subscriber and may affect your account status.
Remember, a well-maintained list will provide more accurate results, and results are what will help determine your next campaign.