microsoft outlook cannot sign or encrypt this message

I am attempting to send from an exchange account, but the underlying exchange account email address has been changed.

The problem is with Outlook - but I'm not sure how to fix it. Just love the many threads on this where the answer is 'uncheck send signed emails'! I'm not looking for a moron's answer.In fact, the certificate is fine, valid and trusted.

Its not clear to me why this isn't consistent or which store of the sender email address drives the certificate 'invalidity' message. I notice that the address book form my user still has the old emailĪddress, even though the exchange mailbox and AD have the new address. Word or acrobat, the same ugly problem arose - however that problem could be fixed by changing the certificates to the old address certificates, even though it was sending from the new e-mail address.Īfter about a day the error message began to occur again for sending new emails from the new address - a problem which could be bypassed only by using a certificate for the old address. However, when using a send as attachment function from This worked fine for sending new emails created direct from outlook. One attempted fix was to remove the exchange account mailbox from outlook and then re-install it again with the new email address. It appears that outlook is in some way 'hard-wired' to the old email address and does not recognize that it has changed for the purposes of determining whether a certificate is 'valid' (meaning in this case not the validity of the certificate,īut whether it corresponds to the invalid email address against which it is being compared in Outlook). Outlook will not raise a problem if I use a certificate for the old email address (but any recipient will see a certificate invalidity warningīecause of an address mismatch), but Outlook raises this error if I attempt to send using a (otherwise valid) certificate for the new address. In fact, the certificate is fine, valid and trusted.

Microsoft outlook cannot sign or encrypt this message