It is therefor important to have the means to display the size of attachments in an email client prior to sending the email to make sure that the email will not be rejected by the mail server due to size limitations.

Displaying email attachment sizes can also be helpful for users who want to reduce the size of their mailbox.

Attachment Sizes is an add-on for the Thunderbird email client that adds size information to all attachments in the web browser. The file sizes are displayed next to each file so that its usually easy to determine the overall size of all attachments. The total size of all attachments is displayed when hovering the mouse cursor over the attachment area in the email client.

This does however only work when sending emails, not when the email has already been received. But the total size is not nearly as important in that case.

Attachment Sizes is compatible with all Thunderbird 3.x clients. It can be downloaded from the Mozilla Thunderbird add-on repository.

Update: The Thunderbird add-on is no longer necessary, as Thunderbird 3 is now displaying attachment sizes by default.

Gmail, Google’s popular email service, has recently raised the attachment limit from 20 Megabytes to 25. This could be interesting for users who regularly send emails with large attachments but also for Gmail users who like to backup files by sending them to their Gmail account. The attachment limit is obviously working in both ways which means that it is possible to send emails with a size of up to 25 Megabytes but also to receive emails that stay below that limit.

The new Gmail attachment limit seems to be enabled on all Gmail accounts already unlike other changes to the email service that usually get rolled out over time. It should also be noted that users need to make sure that the recipients can retrieve emails of that size. It can happen that the email provider refuses these emails as they might be over the size limit of that email service.

If you do get attachments regularly, like digital camera pictures, music, funny pdf or Powerpoint presentations or files like that you know the cause for the huge size of your mail folder. It slows down the application as well and it is a good idea to either delete or remove the attachments from the mails by saving them to a directory on the hard drive.

The Outlook Attachment Remover Add-in (via Shellcity) adds the Attachment Remover button to Microsoft Outlook which becomes active after selecting a folder or message.

It removes (detaches) the attachments from the selected mails in Outlook and replaces them with a link to their location on the hard drive. Some alternatives are to keep the attachments or to add a text reference instead of a link to the mail message when removing the attachment.

Two additional filters are available. The first specifies a minimum file size and the second file extensions that will be processed. If you want to detach all document types you use the format .doc;.xls;.pdf;.pps;.

Subfolders of a selected mail folder can be processed and the folder structure can be retained on the hard drive. I was not able to find information about the supported Outlook editions on the website.

This is probably not a problem for most users but if you do get lots of files of a certain type – at work for instance – then you might want to change the default configuration and lower the risk setting of that specific file type. The following tip is also explaining how users can add new file types to the attachment manager and assign a risk level to them.

We need to open the Windows Registry because the custom settings have to be added to the Registry. Press Windows R, type regedit and hit enter. Now navigate to the Registry key HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Policies. Right-click the Policies key and select New -> Key and name that key Associations.

Three DWORD values define additions to the risk settings of the Outlook Attachment Manager. They are:

HighRiskFileTypes
ModRiskFileTypes
LowRiskFileTypes

If you wanted to add some file types as low risks you would create a new DWORD and name it LowRiskFileTypes. The value of the key can be changed by double-clicking it. Now add file types to it and separate them with a “;”. To add .exe and .avi as a value you would add the following string in that field: “.exe;.avi”