Article ID: 2799505 - View products that this article applies to.

Not sure what release of Office 365 you're using? Go to the following Microsoft website:
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Assume that in a Microsoft Office 365 environment, you try to send or receive files or attachments in Microsoft Lync through Lync Online. In this situation, you may experience the following issues:
  • You can't send files to contacts.
  • You can't receive files from contacts.
  • You can't upload file attachments in Lync online meetings.
  • When you send files to contacts, you receive an error message.


If a user doesn’t see the option to transfer files, verify that file transfer capabilities are enabled for that user. For more information, go to the following Microsoft website:
Configure file transfer, audio-video, and recording
If you receive an error message when you send or receive files, make sure that all the contacts in question have file transfer capabilities enabled and that the file type being transferred isn’t one of those that is listed in the "More Information" section. Additionally, all involved users must meet the network requirements for Lync Online. Use the Lync Online Transport Reliability IP Probe (TRIPP) tool to determine whether your connection to Lync Online has any problems.

For more information about how to use the TRIPP tool, see the "How to verify that all network requirements for Lync Online are met" section of the following article in the Microsoft Knowledge Base:
2409256 You can't connect to Lync Online, or certain features don't work, because an on-premises firewall blocks the connection


Generally, if the menu option to send a file isn't available, this means that the administrator has disabled file transfer capabilities for that user.

If your attempts to upload attachments to a conference or to send files to a contact generate an error message, this means either that the contact that you’re sending the attachment to doesn’t have permission to receive files or that the file type is blocked.

In Lync Online, certain files types are blocked by the Intelligent Instant Message Filter (IIMF) application. IIMF helps protect Lync Online users against the most common forms of viruses without degrading the user experience.

Transferring files to Microsoft Messenger or Skype contacts isn't supported.

By default, Lync Online is configured to prevent users from sending files through IM that have the following file name extensions:
.ade, .adp, .app, .asp, .bas, .bat, .cer, .chm, .cmd, .com, .cpl, .crt, .csh, .exe, .fxp, .grp, .hlp, .hta, .inf, .ins, .isp, .its, .js, .jse, .ksh, .lnk, .mad, .maf, .mag, .mam, .maq, .mar, .mas, .mat, .mau, .mav, .maw, .mda, .mdb, .mde, .mdt, .mdw, .mdz, .msc, .msi, .msp, .mst, .ocx, .ops, .pcd, .pif, .pl, .pnp, .prf, .prg, .pst, .reg, .scf, .scr, .sct, .shb, .shs, .tmp, .url, .vb, .vbe, .vbs, .vsd, .vsmacros, .vss, .vst, .vsw, .ws, .wsc, .wsf, .wsh

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.

Still need help? Go to the Office 365 Community website.


Article ID: 2799505 - Last Review: May 31, 2013 - Revision: 5.0
Applies to
  • Microsoft Office 365 for enterprises (pre-upgrade)
  • Microsoft Office 365 for small businesses  (pre-upgrade)
  • Microsoft Office 365 for education  (pre-upgrade)
  • Microsoft Lync Online
o365 o365e o365p o365a o365062011 pre-upgrade o365022013 after upgrade kb3rdparty KB2799505

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