The best way of identifying email deliverability in large networks such as Facebook, Yahoo or Hotmail, is to use the percentage delivery rate. If the email delivered on a daily basis has a low bounce rate, it is likely that most recipients will visit the link in the email service provider website and browse through the offered content. Likewise, if the email is delivered with a high bounce rate, it is likely that recipients in that particular ISP will not visit the given link and will open the email from the spam folder instead.
Bounce rates can also be determined by examining the sender's opt-in list. A business with a large email deliverability list, where a high percentage of recipients opens email from the spam folder, will probably enjoy a low bounce rate. This means that the emails are read by people who would be interested in the offered content, but not those who have chosen to unsubscribe. On the other hand, businesses with a very small email deliverability list may enjoy higher bounce rates because their messages are rarely read by those who opted-in to the mailing list. Businesses with a very low email open rate will usually have a very low bounce rate.
The combination of these factors, when combined with the delivery time of an email, can determine email deliverability. If the emails take too long to be delivered, the user will start to unsubscribe or delete the message, which may result in loss of future sales and clients. Conversely, if the emails are delivered fast, users will continue to read and may click on links contained in the email before choosing to unsubscribe. However, some ISPs use 'fair-play' rules in their email campaigns, which ensure that emails are delivered at a reasonable rate. The email service provider may also be required to deliver a reply email within certain time frames, which will prompt the sender to respond or not. If the sender fails to do so, his or her account could be terminated.