Well this is a strange issue and many people prefer other launchers, since spb mobile shell is quite expensive. If you access your stock windows mobile contacts, you can also have a look at the mailbox number. Alternatively, it can be found in phone settings.
If both of these numbers are correct, it is spb's fault and for the enormous price, they should fix it.
If indeed these numbers have changed with spb, change them back and see, whether spb destroys it again.
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