Mailboxes & sending domains

A mailbox is the Google account your mail actually leaves from. ColdMerge never sends from its own servers, so every message goes out of a Gmail or Google Workspace account you connect and control.

A sending domain is the part of that address after the @. It is where the public records live that tell Gmail, Outlook, and everyone else that you really did authorise the mail. A Google Workspace mailbox has one. A free @gmail.com mailbox does not, because you do not own gmail.com.

Pages in this section

• Connect and manage your mailboxes covers connecting a Google account, reconnecting one that stopped working, disconnecting one for good, and what each message on the screen means.
• Set up your sending domain walks you through SPF, DKIM, and DMARC, one record at a time, with no assumption that you have ever touched DNS before.
• Send budgets and limits explains the four limits behind “12 of 20 sends left” and how to change the two you control.
• Set your default sending window covers the hours and days new campaigns start out with, and what changing them does and does not touch.

The stance to expect

Almost nothing on the sending domain screen stops you sending. A missing SPF record or a weak DMARC policy is shown as a loud warning, in amber, with the exact fix. The screen says so in as many words: “Nothing here blocks sending.” The one exception is DKIM: an unaligned DKIM that ColdMerge has real evidence of can hold up a campaign launch.

That is deliberate. Poor records make your mail more likely to land in spam, which is a real problem worth fixing, but it is your mail and your decision when to fix it.