Hello ,

We are in the process off implementing new system which requires all school parents (AD Account no Mailbox Enabled or Mail Enabled Recipients ) to have email AD attribute populated with their external email address. Please see image below. Will this change possibly cause any Exchange  issues.

Thank you in Advance

Hi,

Based on my knowledge, for the Mailbox disabled in AD, if you change this mail attribute then enable this mailbox in Exchange. This Mail attribute will be synchronized with primary SMTP proxy address. For the Mailbox Enabled in Exchange, if you change this mail attribute, you will receive errors when you generate the OAB.

Similar thread:

https://social.technet.microsoft.com/Forums/exchange/en-US/1067ece2-22e3-4e73-95cb-b67908821f16/effect-of-mail-attribute-in-ad-user-properties?forum=exchangesvradminlegacy

Best Regards.