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Please uncheck automatically update email addresses based on e-mail address policy and try again
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Thanks for replying! I can see that option for full email users, but not for contacts?
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Fair enough. &nbsp;Let's go the powershell route<br />
<br />
Set-MailContact 'currentemailaddress' -EmailAddresses @{Remove=’emailaddresstobe<wbr />removed’}
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I have found a work-around solution involving using a non-existent domain, which seems to solve the issue (not wanting external contacts to have an address on one of our valid domains:<br />
<br />
<a href="https://social.technet.microsoft.com/Forums/office/en-US/be652bc1-53ec-44cb-9945-d96dc9b6ad54/mail-contacts-and-default-email-address-policy?forum=exchangesvradminlegacy" rel="ugc nofollow">https://social.technet.microsoft.com/Forums/office/en-US/be652bc1-53ec-44cb-9945-d96dc9b6ad54/mail-contacts-and-default-email-address-policy?forum=exchangesvradminlegacy</a>
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Exchange 2016: No matter what I do, I cannot remove or edit the proxy SMTP address for a Contact. Even if I try to edit or delete it, it pops back in again on reopening the dialogu box, with the format John.Doe@contoso.com (of course, the actual name and domain differs)<br />
<br />
Yes, I am logged in with full Exchange administrative rights.<br />
<br />
Any ideas or advise, anyone?
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Exchange 2016: No matter what I do, I cannot remove or edit the proxy SMTP address for a Contact. Even if I try to edit or delete it, it pops back in again on reopening the dialogu box, with the format John.Doe@contoso.com (of course, the actual name and domain differs)

Yes, I am logged in with full Exchange administrative rights.

Any ideas or advise, anyone?

Exchange 2016: No matter what I do, I cannot remove or edit the proxy SMTP address for a Contact

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.