get the name of attachment files without downloading

[soyapark]

https://stackoverflow.com/a/13848096

we could use this to provide a feature of has_attachment() or listing names of attachments

[lukesmurray]

Found the following information here

You have 2 options when it comes to handling attachments.

One is that you download the entire raw message (using the "RFC822" fetch item) and then parse it using a separate package such as email.parser in the Python standard library. This takes care of splitting up the raw message into parts and handles much of the low level details for you. The downside of this approach is that it requires you download the entire message, even if you only care about some parts of it.

The other approach is to use the IMAP fetch command's abilities to download specific message parts. With this approach you would first fetch the "BODYSTRUCTURE" for a message which gives details of the (often nested) parts of an email on the server. This would then be used to drive fetches of specific parts (e.g. "BODY[3.1]". This is somewhat more complicated but can be much more efficient in terms of bandwidth usage.

The relevant parts in the IMAP RFC are https://tools.ietf.org/html/rfc3501#section-6.4.5 and https://tools.ietf.org/html/rfc3501#section-7.4.2.

[lukesmurray]

this library is super useful

[lukesmurray]

also page 73 of this

[lukesmurray]

fixed by #175