Why does the number count in Salesforce and Swift Digital differ in the same shared Mail Group?

The reasons why the number counts in Salesforce and Swift Digital differ are:

1. You have configured your integration not to accept new leads form Swift Digital.
2. SD members will not be added to SF if the company filed is empty.

3. Syncing a member for the first time: Swift digital has rejected some incoming email addresses from Salesforce due to: email address incompatibility with our standards. ( Email validation standard RFC 5322 )

4. Syncing a member for the first time: Swift Digital has rejected incoming duplicate emails that do not have the same First and Last Name
5. Syncing a member for the first time: Swift Digital rejects  incoming duplicate mobiles that do not have the same First and Last Name.