FIX: E_INVALIDARG error occurs when POP3 adapter is used to receive mail that has part name >256 characters or attachment name is base64 encoded

The issue occurs when you use the POP3 adapter with POP3 mail servers that add a base64-encoded "Content-Description:" MIME header field to the MIME of emails with attachments. In some languages, attachments that have long names will cause the following error: 

There was a failure executing the receive pipeline: "Microsoft.BizTalk.DefaultPipelines.PassThruReceive, Microsoft.BizTalk.DefaultPipelines, Version=3.0.1.0, Culture=neutral, PublicKeyToken=TokenID" Source: "Unknown " Receive Port: "ReceivePortPOP3" URI: "POP3://outlook.office365.com#EmailID" Reason: 0x8007005 

After that, the POP3 adapter will stop receiving emails.

This problem is fixed in the following cumulative update for BizTalk Server:

• Cumulative Update 6 for BizTalk Server 2016

For information about the service packs and cumulative update list for BizTalk Server, see the following article in the Microsoft Knowledge Base:

2555976 Service pack and cumulative update list for BizTalk Server

For more information about BizTalk Server hotfixes, see the following article in the Microsoft Knowledge Base:

2003907 Information about BizTalk hotfixes and Cumulative Update support