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Winmail.dat Attachments Outlook Issue

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Last Modified: 2020-09-18
I have a client who is unable to receive emails with attachments from a particular address.  The emails come in with an attachment of winmal.dat instead of the PDF attachment that should be there.

The client is using an iMac that is about 5-6 years old.  It has osX version 10.11 installed.  It also has Office for Mac 2011 with updates to 14.2.1 (I think that is correct).

At the moment it seems to happen when we send email to her email address from an Office365 managed email address.  The O365 managed address is a reasonably new domain set-up in the last 3 months.  The O365 domain email address does not have issues with the majority of emails they send to other addresses.

My reading has been that the issue is with the iMac and possibly the Office software.  If we configure the same email address that is on the iMac on my PC in Outlook, the emails receive fine with the attachments.  In my opinion this rules out the sends O365 domain as the issue.

Today the O365 sender contacted me to say another client of his has had the same issue this morning on an email from him, so he is adamant it is the O365 setup.

I still dont think it is.

Can anyone assist with their experience of the winmail.dat email attachments issue
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MaheshArchitect
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Commented:
when exchange send emails to rtf format, some clients don't understand that format and display original mail as attachment (webmail.dat)
setup the o365 customer domain as remote domain in O365 console and set rtfenabled to fase
this will ensure that exchange send emails only in html format always
MaheshArchitect
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I mean winmail.dat

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I dont understand what you mean by setup as remote domain.  Also where is the setting for rtfenabled in the Office365 Admin
MaheshArchitect
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Commented:
https://technet.microsoft.com/en-IN/library/dn743842(v=exchg.150).aspx

Refer above link to create remote domain and set rtfenabled to false
Irwin W.There are a 1000 ways to skin the technology cat.
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Commented:
Please ask you client to request emails from their contact be resent to them as plain text.

Here is what the send of the email needs to do
https://support.office.com/en-us/article/change-the-message-format-to-html-rich-text-format-or-plain-text-338a389d-11da-47fe-b693-cf41f792fefa
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Instead of changes, providing information to the recipient to be sufficiently comfortable with working with the winmail.dat attachment and be done with this issue once and for all as other senders may have similar, and you can not expect that each sender will be persuaded to accommodate the outlined change as it is merely an inconvenience to some but not a functional impediment.

Winmail.dat kicks in when there are multiple and the client in use does not unpack it.

Helping the recipient/s understand how to handle a receipt of a winmail.dat attachment is ......
MaheshArchitect
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instead of repairing issue on client level better resolve it from server end

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Commented:
nappy_d:  the issue is with the clients emails being sent out, not receiving emails.

mahesh - when I checked his Outlook options in File, Options, Mail, the Compose messages in this format option was already set to HTML


Still no more informed on this....
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check whether the sender sends attachments as INLINE versus as attachments.
Composing is HTML? Signature with images?

The setting on the receiving end might be different i.e. it does not unpack the winmail.dat .....

Author

Commented:
Yes html with signature and images in.  

Others on his same domain had the issue but then it disappeared for them

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