Hey @pgr thank you! I was able to create it with logic hooks. I stills truggle with one thing. My logic hook is after_save and each attachment (each one is different) has 3MB.
When I set the logic hook in a way where it triggers during file upload (after save and then condition - file field not empty) it sends email OK but the file has no .pdf extension and the name has UUID.
BUT - when I upload the attachment first and THEN change anything in any other field it send the email with attachment in correct format with pdf extension.
Now - I think that the problem here is that the logic hook triggers immediately when I am still uploading the big file and although it sends it correctly it probably fails to correctly get filename and file_mime_type from its bean.
And I also found another issue - but this one seems to be related to SuiteCRM native behaviour. I can’t upload files in listview. It simply fails (field stays empty after upload). I have to do it in edit view.