Hi!
 

A good quality contact database primarily affects better deliverability, so it is necessary to regularly take care of the hygiene of the database to help keep it in good quality. 

How to take care of database hygiene?

• use doble opt-in - this allows you to maintain a good quality database, and above all to avoid the problems of providing false or not their e-mail addresses;
• remove regularly inactive contacts from the list, we can do this with automation rules, e.g. tag contacts that haven't opened an email in a while, and then we can try to encourage them to e.g. visit our website/start opening e-mails by dedicated campaigns. If it won’t work we can remove these contacts;
• remove invalid email addresses from the database; 
• it is also important that the addresses in the contact list do not come from the same domain and are not generic addresses (e.g. info@, office@, office@;
• remove hard bounces  after checking the bulk mailing analysis.
  
  Have a nice day!