Winmail.dat Attachment Outlook

WebBanshee — Tue, 17 Jan 2017 07:57:20 +0000

You get reports that external recipients receive attachments as winmail.dat attachment ( or sometimes ATTxxxxx ). The cause is the format that has been used to send the mail. This behavior occurs in most cases when an email with attachment has been sent from an Outlook Client and the external recipient does not use Outlook.

Please note that this description is only for Outlook 2010 clients!
Find a description for later clients here

However, to solve this issue on client side, the external recipients having this problem, should be present in your Contacts folder.

> Open the contact and double click it’s email address
> Expand the right icon and choose Outlook properties

> Choose unter Internet Format : Send Plain Text Only

> Click OK and resend the mail with attachment to this contact.

It does not help to specify in the settings to send Emails in HTML format. You need to force it on the recipients.

See a server side solution here :

Winmail.dat Attachment Exchange

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Winmail.dat Attachment Exchange

WebBanshee — Mon, 16 Jan 2017 17:27:08 +0000

When external recipients complain about receiving attachments in winmail.dat format ( or sometimes ATTxxxxx) this is most likely caused by the formatting. To be more concrete it is caused when Exchange uses RTF ( RichTextFormat ) for sending mails to external recipients.

To solve the winmail.dat issue on serverside the external recipients should be added as Mail-Contacts to the Exchange organization. You can force Exchange to never use RichTextFormat when sending mails to these Mail-Contacts.
To force Exchange to never use RTF format when sending to external contacts use :

Exchange 2010 Multi-Tenant : ( for a certain Mail-Contact )

Get-MailContact -Organization “TenantName” -Identity “Mail-ContactName” | set-mailcontact -usemapirichtextformat never

Exchange 2010 Multi-Tenant : ( for all Mail-Contacts in an organization )

Get-MailContact -Organization “TenantName” | set-mailcontact -usemapirichtextformat never

Exchange 2013 / 2016 Multi-Tenant : ( for a certain Mail-Contact )

Get-MailContact -OrganizationalUnit “TenantName” -Identity “Mail-ContactName” | set-mailcontact -usemapirichtextformat never

Exchange 2013 / 2016 Multi-Tenant : ( for all Mail-Contacts in an organization )

Get-MailContact -OrganizationalUnit “TenantName” | set-mailcontact -usemapirichtextformat never

For Exchange OnPremise you should most likely use these CMDlets without the -Organization or -OrganizationalUnit switch.

You can also consider to use the Remote Domain solution.

Since we only have Multi-Tenant environments we want to control this on organization level. For this reason we did not mess with the Remote Domain. Hence we have not tested it. But a comment on this from someone , who has implemented the Remote Domain solution in a Multi-Tenant environment , would be well appreciated.

This will solve the problem on serverside. Attachments will not longer appear as winmail.dat files.

See a client side solution here :

Winmail.dat Attachment Outlook

The post Winmail.dat Attachment Exchange appeared first on Webbanshee.

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Winmail.dat Attachment Outlook

Winmail.dat Attachment Exchange