Email Communication: Guidelines
Reputation is Everything
The main algorithms used by ISPs to identify spam are based on the sender's reputation. Reputation is measured differently by every ISP, but some basic principles hold for all ISPs:
- The customer complaint rate is the primary input. That is, every time someone clicks the "This is Spam" button, your reputation takes a hit. As long as complaints are below 0.1%, your reputation is safe. With anything higher, your reputation starts to suffer.
- It takes time to gain the ISPs trust. Some senders require time before the ISPs allow their mail to reach the inbox. Live mail from Microsoft currently has the most stringent rules about bulk mailings until they trust you.
- Spam traps are the second most important input. ISPs use abandoned accounts to watch for unsolicited email. As a result, you should not email any address that has not had activity in 90-180 days, preferably 90. While this is unfair to legitimate senders (perfectly legitimate addresses can suddenly become spam traps), it is a standard practice in today's email world.
- Consistent mailings help maintain reputation. Mailings of similar size and with regular frequency can help maintain your reputation. Inconsistency can reduce your overall reputation.
- Overmailing can hurt your reputation. Mailing too frequently can hurt your reputation. Though there is no "magic number", twice a week does not hurt reputation, but four times a week does.
One Bad Message Can Hurt You
It is crucial that you understand this point. Even a single message sent to an old or suspect list can do lasting and substantial damage to your reputation and your ability to deliver.
We want you to have long and productive relationships with your customers. Maintaining a high level of vigilance regarding email quality greatly improves your short and long term success. If you are in doubt about anything regarding email practices, talk to your client services manager before you send another message.