Skype File Transfer Guide
Skype for Business may not connect properly if it’s installed in a cloud or intranet environment.
In a hybrid environment with remote access VPN connectivity, the issue may be that the client has failed to establish an appropriate connection to the VPN.
Make sure Skype for Business isn’t running on a disconnected computer or if it is installed in a cloud or intranet, make sure there are no connectivity issues.
If possible connect the client to the network and verify that it is working.
When installing Skype for Business in a hybrid environment with remote access VPN connectivity, make sure that the server credentials are configured and that they have been used to connect to the server or proxy server (if applicable).
Is Skype for Business file transfer turned off?
In Skype for Business, file transfers are done with the “Send To” and “Receive From” buttons in the contact list.
Files can also be transferred via the Share button on the Skype for Business home page, which will either send a file to a contact or open it in the default program for that type of file.
As an aside, while I was researching this article, I stumbled across this useful Microsoft TechNet page on Skype For Business File Transfer Protocol (SFTP).
SFTP is the official protocol used by both Microsoft and Skype for Business to transfer files. It is similar to FTP, but more secure.
As mentioned above, in order to send a file using the Send To option in Skype for Business, one must have previously added the contact to the Send To list.

If you have not done so, please go to Skype for Business > Contacts and add a new contact. Once added, select File Transfer from the Contact’s Tools menu or from within Outlook on your PC/Mac.
You will then be prompted to enter the email address of the contact you wish to send a file to.
Skype for Business will then ask if you want to send this file from your PC/Mac or from Skype for Business.
You can select “Send From Skype For Business” and proceed with sending the file.
Inter-company or Microsoft team file transfer
Microsoft Teams can be used to transfer files between users in different companies or domains. To accomplish this, you will need to ensure that both the sender and the receiver are currently using Teams.
You can also transfer files between users of different Microsoft Teams domains or Microsoft domains.
If a file is being transferred from one user to another on the same domain, then it will be sent using a Microsoft Office Communications Server 2007 R2 application. If the sender and receiver are on different domains, then it will be sent using an Internet Message Access Protocol (IMAP) connection.
Outlook Web App for File Transfer between Companies, Teams, and Domains
2021 will be the year for federating Teams with Skype for Business. By utilizing the above technology, one can communicate with external companies using Skype for Business.
Depending on the company, federation can be enabled for specific domains or for everyone. Skype for Business on-premises or online can enable federation. Sometimes a hybrid environment may exist.
In Island Mode (both clients have installed the same features on their PCs), Skype for Business is the default chat and calling client. Messages sent by a federated user will be received by the Skype for Business client.
Skype for Business won’t let you send certain file types, due to malware risk. Here’s the full list of files Skype for Business (Server and Online) blocks:
Compliance: When should File Transfer be turned off?
Surprisingly, there IS a situation where you would want to turn File Transfer off, and leave it off. When you have to maintain a regulatory compliance standard.
In Skype for Business Online, file transfers within Instant Messaging are considered a “non-archived feature.” That means the feature isn’t captured when you have an In-Place Hold set up in Exchange. Thus the data you would send via file transfer doesn’t get recorded…which can jeopardize compliance.
Microsoft Teams can be used as an enterprise UC solution for those users who are not yet on Skype for Business.
File transfer in Skype Meetings is enabled by default and there is no way to turn it off without using a PowerShell cmdlet.
You can turn file transfer off in Skype for Business with Set-CsConferencingPolicy. Here’s how:
Teams doesn’t let you turn off file transfer within the browser. So there’s no equivalent to “Set-CsConferencePolicy”.
Skype for Business Not Working?
Are you aware that Skype for Business has some features that don’t work, such as file transfer? File transfer in the internal premise network is not possible for Skype for Business users. You may need to check the following.
Millions of people across the world have benefited from Skype’s endeavor to improve their lives.
Skype is one of the most popular apps ever. Calls and messages between mobile devices and computers are some of its most notable features. Here are a few other ways you can utilize this technology to your advantage.
It may not work properly if Skype for Business is installed in a cloud or intranet environment.
Fixes for Skype for Business File Transfer Issues
What is happening?
The file transfer process fails on the Skype for Business Server.
Where is this happening?
On a Skype for Business Server that has been updated to version 16.0.8735.4088 of the Windows Server 2012 release.
When does this happen?
This issue occurs after an update to Windows server 2016 or Office 365 ProPlus is installed, and it typically appears around 2 hours after the update was applied, but it can take up to 12 hours for the issue to manifest.
The file transfer process fails when a user tries to send files over an instant messaging (IM) connection in Skype for Business Server.
What happens?
When a user sends a file from Outlook or SharePoint, the following error occurs: “An unexpected error occurred during the file transfer operation. The following error was returned: -2147217259”
This issue affects Skype for Business Server only, and not Skype for Business Online or Teams.
Problem:
Skype for Business is a robust and versatile tool that enables users to work from anywhere.
Agitate: The issue can be resolved by checking the network connectivity of your system or contacting your IT team, based on whether you are using Skype for Business in pure cloud or intranet environment.
Solution:
If you are unable to do file transfer in the internal premise network of Skype for Business users, you may need to check the following.
1. The “For compliance, turn off non-archived features” option is unchecked.
For the steps, you can refer to: https://support.office.com/en-us/article/Configure-settings-for-individual-users-77B26EAC-8228-4161-BA9F-733B187BD836
2. External Skype for Business and Skype users have turned on external communications.