Cleaning your data

All you need to know about how to have and maintain a clean database.

Written by Anthony Green
Updated over a week ago

Data cleaning is all about keeping your data accurate. Accurate data leads to better email read rates, better interaction, and overall a better result from your database as a whole, while also ensuring that your email sending reputation is not harmed.

Why should I clean my data?

If you send an email campaign to data that hasn’t been cleaned, it is likely your email will soft or hard bounce. A hard bounce represents a permanent reason we couldn’t deliver the email, often caused by a typo in an email address, or an outdated address. 

Each time you send an email campaign to unclean data, and each time that email is bounced, this will harm your sending reputation. This is why we recommend data cleaning as a first step before you send email with Airship.

What makes my data ‘unclean’ ?

There are common reasons behind unclean data.

Email addresses

  • Incorrect formatting: Email addresses follow a format of “accountname@domainname.suffix”. Any addresses that don’t follow the format will not be accepted by Airship. By design, emails with invalid formatting cannot exist in your Airship account.

  • Invalid domain: Airship checks that the domain has an email server actively associated with it. This means that email addresses using non-existent email servers will be rejected by Airship.

  • Fake data: Users sometimes try to circumvent email validation, by using the correct formatting, and a valid domain, but providing a non existent account name. Airship allows these addresses as they are technically valid, but an email cleaning service will identify these so you can remove them.

Mobile numbers

Airship expects mobile numbers to follow the UK’s mobile number format. By design, any mobile numbers that do not follow this format are rejected.

Airship’s built-in validation checks for international numbers, rejecting them, and validates that the number is a valid UK mobile number. The key part here is that we check it begins with 07 and contains the digits 0-9 after this.

UK mobile numbers are 11 digits long. Airship will accept mobile numbers beginning with 44 and 07.


Airship expects post codes to follow the UK’s postcode format. By design, any post codes that do not follow this format are rejected. We adhere to the U.K. Government’s Valid Postcode Format guidelines.

Cleaning your data before it’s in your Airship account

If you have historic data to import in to your Airship account, or data from another email or CRM service, we recommend it is first cleaned using a data cleaning service. These paid-for services offer an easy way for you to remove fake or non-existent email addresses from your data list. Below is a list of services you can use:

Cleaning your data once it’s in your Airship account

Airship has built-in functionality which will clean your data each time you send an email campaign.

  1. Hard and soft bounces. Airship cleans email lists automatically based on hard bounce and an algorithm for soft bounces. This shows the ESP (Email Service Provider) that our clients are responsible senders and builds trust. If you want to learn more, read our “Problems with emails not being received?” article.

  2. Retention. This is an automatic way of cleaning data from your account, read “How to set up a Retention Email” to get started.

Now that your data is clean you are ready to complete your import! Click here if you want some tips on how to do this. 

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