User account being given Send As permission on All mailboxes- Exchange Online - Can't Remove

I have a user with username 'Self' - full name i.e.  'Self, Adam'   I have a Hybrid set up.   For some reason, when I migrate a mailbox to the cloud, this user is given Send As permission to the mailbox. This occurs also when i create a new mailbox in the Cloud. Knowing there is an attribute called Self in ea mailbox, I renamed the username to 'Self1' After a dirsync, I can not remove the 'Self, Adam' user from the Send As permission. The error says, 'the ACE isn't present.  How can I remove this user?
Anthony K O365Asked:
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AmitIT ArchitectCommented:
You did a mistake by renaming the account. As it no more exist. Better open case with O365 support team.

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Anthony K O365Author Commented:
I don't think renaming the account was an issue b/c the permission is being inherited from somewhere as it gets added to every new mailbox. I will get with Microsoft.
Anthony K O365Author Commented:
I've requested that this question be deleted for the following reason:

Not needed at this point
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