I have 2 end users that are unable to send attachments to certain vendors. The email goes through with no attachment. This is not for every vendor and we are not aware of any of the other 300+ end users having this issue. The 2 users only have one vendor in common, however I was able to send an email with the same attachment without any issues. If the vendor sends a reply, the user can attach to the reply and the attachment will go through.

The six vendors have no common domains.

Hi,

In order to fix the issue more efficiently, I'd like to clarify the following questions:

Does the attachments show in the sent emails in the two users' Sent Items folder?

Does this issue continue if we send the same attachments to the venders from webmail?

In which format did you send the email? Have you tried switching between HTML/RTF/Plain Text and send the email again to see the result?

Does the two vender use Microsoft Outlook as the email client to read email messages?

Regards,

Steve Fan
TechNet Community Support

Hi,

This can happen, if the user sending email in RTF format and the message does not get converted to the HTML or Plain Text format. Especially in the case where they receive a winmail.dat attachment.

Make sure that yiur default compose format is not set to Rich Text and to verify go to:

Outlook 2010
File > Options > Mail > Compose messages in this format.

Regards