A folder holds hundreds of EML files and I need the attachments out of all of them into one folder, the messages themselves irrelevant.
What handles a directory of EML files in bulk for attachment extraction?
Extract attachments from EML files in bulk
Solved Email & Outlook
BA
Barry Allen November 3, 2020
2 replies
5,680 views
Reviewed by moderators
Each EML being a single MIME message, a directory of them is even simpler to process than an MBOX since the messages are already separate files and the routes mirror the MBOX case:
The script route: a Python loop over the directory, parsing each .eml with the email module and walking its parts to write out attachments, is a dozen lines with no dependencies. It filters by extension, prefixes filenames with the source EML name or a date to prevent collisions and clears hundreds of files in seconds. The directory of separate files actually makes the script simpler than the MBOX version, no message boundary parsing needed.
The no code routes: Thunderbird with ImportExportTools NG imports the EML directory and extracts attachments across the resulting folder, and various attachment extractor utilities take a folder of EML directly with a progress bar and naming options. Either suits when scripting is unwelcome.
The one detail EML adds over MBOX: attachments referenced but stored separately, rare but present in some EML exports where the message points at an attachment file beside it rather than embedding it. Standard extraction gets the embedded ones and a glance at whether your EML files have companion files beside them catches the referenced ones, usually a non issue with EML from normal mail clients where everything embeds.
The same collision and inline decisions apply: date or source name prefixes so nothing overwrites, and filtering inline signature images and tracking pixels from genuine attachments so the output folder holds what you actually wanted rather than hundreds of one pixel gifs.
Python loop over the directory, filtered to documents, source name prefixed, done in seconds. My EML files all embedded their attachments so the referenced file caveat did not apply. Inline filtering kept out the tracking pixels beautifully. The separate files being simpler than MBOX proved exactly true.