From: roberto huertas roberto on
When I send an attachment using Outlook 2007, the receiving end sees it as a
winmail.dat on mobile devices? (i.e i-phones) and therefore can not be opened.
The same mobile device receives regular attachments from other users without
any problems.
From: VanguardLH on
roberto huertas wrote:

> When I send an attachment using Outlook 2007, the receiving end sees it as a
> winmail.dat on mobile devices? (i.e i-phones) and therefore can not be opened.
> The same mobile device receives regular attachments from other users without
> any problems.

Recipients of e-mails with .dat attachments are those who are NOT using
Outlook. TNEF format (which is one RTF spec) is a proprietary document
format from Microsoft that only their Outlook e-mail program can understand.
Not even Microsoft's Outlook Express understands RTF. That means the only
recipients of your RTF encoded e-mails that can view them as you composed
them would be those that are also using Outlook as their e-mail client (or
those that have installed a separate 3rd party RTF viewer app).

The only time you should use RTF is when you can guarantee the recipient
also uses Outlook (and that both sender and recipient are within the same
Exchange server organization), like within a corporate environment where all
employees are required to use Outlook. Since you cannot guarantee what
e-mail client is used by an Internet recipient, compose your e-mails using
plain-text or HTML format.

For information on Microsoft's proprietary TNEF format, read:
http://support.microsoft.com/kb/290809
http://en.wikipedia.org/wiki/TNEF

There is an option in Outlook to ensure that Internet recipients get your
e-mails in plain-text or HTML format. So you could use RTF for your
intranet recipients (i.e., everyone in your network that is using Outlook)
but also ensure that your e-mail gets converted to plain-text or HTML format
for your Internet recipients. In Outlook, go to:

Tools -> Options -> Mail Format -> Internet Format -> Outlook Rich-Text
options

Select "Convert to HTML format" from the drop-down listbox, or select
plain-text if you don't want to bloat your e-mails with unnecessary HTML
coding.