A mailbox is the only thing Colldly needs from you. We send from your addresses so reputation and replies belong to you. This guide shows the exact settings for Google, Microsoft and your own hosting, and what to do when the connection test fails.
Mailbox passwords are encrypted in Colldly (AES-256-GCM) with a separate key that is not stored in the database. For Google and Microsoft use an app password, not the account password.
You need the SMTP and IMAP server addresses, ports and login details. You find them in your email provider's help, usually under "mail client settings".
Turn on two-factor authentication and create an app password. Your normal account password will not work. The server is smtp.gmail.com on port 587 and imap.gmail.com on port 993.
You need an app password here too. In some organisations SMTP is disabled and has to be enabled by the administrator. The server is smtp.office365.com on port 587.
With ordinary web hosting use the details of your email account. The ports are usually 587 for SMTP and 993 for IMAP with encryption.
After saving, run the test. It verifies that the mailbox really sends and receives. Only once the test passes does it make sense to add it to a campaign.
Add a signature and choose where replies should be collected. With several sending addresses it pays to route replies into one mailbox you watch.