Outlook 2010 30MB Outlook 2007 30MB Email Compression Tools You'll double click on the saved file to install it in your registry.ĭownload a ready-to-run registry file to set the maximum attachment size to 30 or 50 MB:

You can can change the dword value in code below if needed (its set for 30 MB) then copy and paste into notepad and save as 'MaximumAttachmentSize.reg'. The Send and Receive Progress Dialog will show this error: If the MaximumAttachmentSize is set higher on the client than the Exchange account is allowed to send, the message will not send. Exchange 2010 users will see a mailtip above the To field instead of the warning dialog. Outlook wastes a lot of time uploading the huge file that will never send and this prevents the sending of any other mail.Įxchange server accounts should use the message size set for the user account. This limit eliminates the problem with stuck messages: If you try to send a message using SMTP, you get an NDR back into your Inbox telling you the message is too large. Because Outlook can't query a SMTP for the maximum attachment size, it uses a default attachment limit of 20 MB (20480kb), which is about right for most ISPs. In order to reduce NDRs and failed sends, Outlook checks the message size before sending and alerts the user that the message is larger than the mail server allows. 'The attachment size exceeds the allowable limit'.

Default attachment size office 365