Probably not, but check the community plugins. I vaguely remember seeing something recently that claimed to be able to do that (but I might be misremembering, or it might have been something outside of Obsidian).
You could also research options for extracting those emails from the PDFs so you could store them in a more flexible format.
As a workaround, you could write the page number of each email you want to link to. Then instead of clicking a link, the flow would be to click the link, write the page number in the page number box, and press Return (or scroll if Obsidian’s PDF viewer doesn’t have a page-number box). It’s slower, buy maybe acceptable.