Glossary
What is a daily sending limit?
A daily sending limit is the most emails one mailbox may send in a day. It keeps a sender looking like a person rather than a machine, protects the mailbox's name with mail providers, and keeps one bad day from doing lasting harm.
Why have a limit?
Mail providers judge each mailbox by how it behaves. A person sends a few dozen emails a day, spread out. A mailbox that sends hundreds at once, or doubles its volume overnight, looks like spam, whatever the emails say.
How high should it be?
Lower for a new mailbox, rising slowly as it builds a history of mail that is delivered and answered. If you need to reach more people, more mailboxes at a modest limit each is safer than one mailbox pushed hard.
What does Propel do?
Each mailbox you connect has a limit of 30 emails a day to begin with, fewer while it warms up, and its sends are spaced out across the day rather than fired at once. See the guide Connect a mailbox and send safely.