It moves cleanly, and it arrives with its consent intact
Download your subscribers from wherever they live now and bring the file. Anyone with a clear record of having said yes goes straight in. Anyone without one — an old list, a date nobody wrote down — is held back, and no message goes to them until you have asked once and they have said yes. That is slower than a platform that mails everybody regardless, and it is the difference between a list and a liability.
- Check it
- Upload your list, then download it again before you have paid anything
The technical bit, if you want it
A spreadsheet import that matches your columns, holds back any row with no demonstrable record of consent, and asks those people once.