SQL server express - exceed your licensed limit of 4096 MB

I know nothing about SQL other than the fact that there's some software on one of my servers (Server 2003) that uses it. I started getting this error yesterday.

CREATE DATABASE or ALTER DATABASE failed because the resulting cumulative database size would exceed your licensed limit of 4096 MB per database.

Along with this one:

Could not allocate space for object 'dbo.EXCHANGEPAMDAPOOL'.'PK_EXCHANGEPAMDAPOOL' in database 'SEAExchangeDB' because the 'PRIMARY' filegroup is full. Create disk space by deleting unneeded files, dropping objects in the filegroup, adding additional files to the filegroup, or setting autogrowth on for existing files in the filegroup.

So, it's my Metalogix Exchange archive software. That much I've figured outfrom the errormessage. We no longer have support with them because we are moving to O365 - original plan had...