Remove irrelevant leads and contacts because it can be harmful to your email marketing success. Doing this can increase your deliverability and sender reputation moreover it improves your email open rates, saves you money as well if you're charged on a per-send basis. Hope you are now convinced with the importance of keeping your email list clean, but how you will do it? Here is the solution, remove all such kind of email address from your list. Following are the types:
a) Disengaged Email Recipients: Those recipients which has stopped opening your emails, initially they shouldn't be erase from your list immediately. Because they can be ask for feedback which gives them opportunity to change their opt-in settings, but yes after your re-engagement attempts if some of the recipients are still disengaged subscribers, then you should proactively erase them from your list before they damage your reputation and mark you as SPAM .
b) Duplicate and Invalid Email Addresses:. Every email address should be checked to confirm that it is a real and working or not.
c) Unsubscribed Email Addresses: Those who unsubscribes or opt out they should also be removed from your email list. It is mandatory.
d) Contacts Who Didn't Opt In: Anyone who didn’t subscribe your mails should be removed as this will not only help keep you out of the clinker, it will also help improve sender reputation, email deliverability, and open rates.
e) Alias Email Addresses: Alias addresses are like email@example.com ,firstname.lastname@example.org . Many ESPs don't deliver emails to these types of addresses successfully because such kind of email addresses associated with the alias has opted in to receive communication from you.
f) Bouncing Email Addresses: There are two types of bounces that is Hard bounces, and soft bounces which should be consider while erasing. Soft bounce might occur because the recipient's mailbox is full it, hard bounce occur when email message that has been returned to the sender and is permanently undeliverable because of invalid address or the email recipient's mail server has blocked your server, Soft bounces should be monitored continuously. If their bounce rate does not reduce they should be removed from your list.
g) Too Old Email Contacts: The older the email address, the more likely they are good stuff for removal because the recipient have lost interest in your product/service. But those who are giving complaints of SPAM or those emails which are abandoned, or those who have changed their email addresses or those who are not at all interested in your product or service. Remove them from your list.