The email cleaning list is the most effective technique to keep your database healthy and free of unwanted contacts that can stain your IP's reputation as well as harm your relationship with those who are truly interested in receiving information for your business.
Even for poor email accounts that will not be delivered, credits will be charged — the bigger the number of subscribers, the higher the mailing cost.
If your list is out of current and you continue to send emails to these addresses, your company may be flagged as spam for not verifying the quality of your contacts. Even if the message is relevant to the rest of the recipients, it will be filtered as spam.
It is a long established fact that a reader will be distracted by the readable.