Mailing list cleaning/data scrubbing is a legitimate practice in both email and offline marketing. In fact, it's the most crucial component to list hygiene. This is also partly why some companies prefer to use leased lists (though this can be considered spammy, especially if you aren't careful about the source), as such lists are professionally managed and kept clean of duplicates and dead/outdated addresses.

A professional list cleaning service should be able to help you merge/purge and split your mailing lists and scrub invalid addresses. But you should also make sure you're removing bounced addresses as using e-mail analytics to check your lists for inactive addresses. Using a double opt-in list and maintaining clear unsubscribe instructions in each e-mail (and an automated unsubscribe system) is the other half of the puzzle. This way your lists will keep themselves clean and you won't need professional list cleaning services as often.

Mailing list cleaning/data scrubbing is a legitimate practice in both email and offline marketing. In fact, it's the most crucial component to list hygiene. This is also partly why some companies prefer to use leased lists (though this can be considered spammy, especially if you aren't careful about the source), as such lists are professionally managed and kept clean of duplicates and dead/outdated addresses.

A professional list cleaning service should be able to help you merge/purge and split your mailing lists and scrub invalid addresses. But you should also make sure you're removing bounced addresses as they come in and using e-mail analytics to check your lists for inactive addresses. Using a double opt-in list and maintaining clear unsubscribe instructions in each e-mail (and an automated unsubscribe system) is the other half of the puzzle. This way your lists will keep themselves clean and you won't need professional list cleaning services as often.