Sometimes it’s necessary to select a list of email addresses which are not part of another list of email addresses. One use case would be a publisher matching his subscriber list against a suppression list of an advertiser. The suppression list holds users who don’t want to hear from the advertiser anymore. So it makes perfect sense to exclude them from the upcoming email send.
How can you achieve such an address matching efficiently on your computer? One way would be to use a database like Microsoft Access. A data manipulation tool like R offers another possibility. Here is a quick step-by-step guide for the latter one: Continue reading