Attachment location on server

Can someone please tell me where can I download attachments that are sitting on my mailbox server ? Rather than downloading it from the webmail I can’t to get it directly off the server . I know about the location on the server for sent and receive emails but can’t find where attachments would be stored ? Such as PDF files

Thank you

There is no attachments file as such in mail server.
Attachment is specially encoded part of plain text mails stored
/home/user-data/mail/mailboxes/domain.tld/username
in maildir format.

If you need to download attachmens directly (and nothing else), then simple solution would be some sort of imap client specially intended for that.
Enter “imap attachments downloader” and you get many choices to choose from.