When a person goes to OWA and tries to customize the signature, they get a message that the signature is too big.
- -go to EMS:
- -type: Get-MailboxMessageConfiguration foo.user
You will see the SignatureHtml. Most likely, there will be inline css styles in the signature pushing the character limit.
Or the DefaultFontSize is greater than what is acceptable. The following should clear the clear the signature-text and the signature-html. Then have the account try again to set the signature:
- -type: Set-MailboxMessageConfiguration -Identity user -SignatureText $null -DefaultFontSize 7