What is mail channel warm-up?

Email channel warm-up is the process of gradually increasing the volume and frequency of sending to a new email sender or mail server in order to build a good credibility and trust before starting to send large volumes of emails to them. This process is designed to avoid being perceived as a spammer or facing delivery problems. By warming up an email channel, senders can gradually build trust with their email service provider (e.g. Gmail, Outlook, etc.), increase their email delivery rates, and ensure that their emails reach their recipients' inboxes.