Email list cleaning needs to be robust and move mountains. When an email marketer cleans their list, they send to it immediately, so the timing is essential plus the size of the file needs to be just right for the correct conditions. Many email marketing systems use different formats so every email marketer should own parsers and appending software to manipulate their databases so there are not errors when it comes to sending mail.


Email cleaning companies and service providers use several different delimiters for their system. The average is comma with semicolon in second place. Some use pipe delimiters and colon but comma is what most email list validation service uses. Separating your data is so important. Many use a semi colon because some data uses comma only to separate data inside one cell. In example, some data has/have sentences with periods. In this case, using a comma to separate is a bad idea, therefore semi-colon is the right choice.

Multiple Columns

It’s rare to find email verification free, let alone a company that will not support multiple columns. Most data comes with name, email, phone and hundreds of other combinations. These are called “headers” and with that comes multiple columns. If an Email list cleaning company does not support multiple columns, then that is a red flag. Professional systems should support at least a million records and with multiple columns.


There should be no reason to scrub any more than 1 million records at a time. We have clients upload hundreds of files into our FTP utilizing our batch API and can get the files out quickly. A typical file with 1 million records and multiple columns can be up to 250 mb. Anything over that is not necessary since most lists are not as big as that anymore. There was a time, ten years ago, where these lists were needed cleaned, but hygiene and email marketing has changed since then. Most lists are now smaller and targeted versus the shotgun approach.


Excel can open up to 1.2 million records. Anything over that, it will show an error. Use excel as a rule of thumb on sizes of files you need scrubbed. If your database is larger and you need to open it up to cut it down, TextPad for windows works well and BBEdit if you use MAC. Both applications can open up at least 1 gb files.