Sends twice the size of the email

Asked by Don Task

When I send an email with an attachment, the total size of the attachment is displayed by evolution, however, when I watch the network traffic for the send and receive bytes, the send size is virtually twice the volume of the email size. For example, a text email with an 11mb attachment, will be sent at about 22 mb.

Is there a background email address that evolution is sending to that is hidden to me?
How can I view the traffic and destinations related to the email being sent?

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: evolution 3.2.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-14.23-generic 3.0.9
Uname: Linux 3.0.0-14-generic i686
ApportVersion: 1.23-0ubuntu4
Architecture: i386
Date: Mon Jan 16 23:32:58 2012
ExecutablePath: /usr/bin/evolution
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
SourcePackage: evolution
UpgradeStatus: Upgraded to oneiric on 2011-12-22 (26 days ago)

Question information

English Edit question
Ubuntu evolution Edit question
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Solved by:
Marc Deslauriers
Last query:
Last reply:
Revision history for this message
Don Task (syntactics) said :

This incident may be specific to the user and not an evolution problem in and of itself. Perhaps other users should watch the outgoing traffic when sending an email with a known attachment size, such as 1 mb and determine if they also observe the same effect.

Revision history for this message
Best Marc Deslauriers (mdeslaur) said :

Sounds about right once the attachment is mime-encoded. Encoding the attachment so it can get included in email, which was originally designed for text, can make it's size grow to practically double it's size.


Revision history for this message
Don Task (syntactics) said :

Thanks for the reply. I followed the wikipedia link and learned quite a bit, however, I was not able to determine that this is the actual cause, but I accept that it most likely is. Since the attachment I send was a PDF, the explanation sounds correct that it would be necessary to MIME the pdf to allow it to be handled as a text email.

Thank you again.
Don Task