RePEc sends monthly updates by email to authors, editors, and archive maintainers. The email addresses are taken from the data that is provided by the recipients. If they fail to maintain these addresses when they move, RePEc may not be able to contact them any more. This post describes what happens under such circumstances.
Once an email bounces after the monthly mailing, we put a notice wherever contact information may appear on IDEAS or EconPapers, encouraging readers to provide an alternative email address. While a RePEc administrator can update an email address in an author’s record, for RePEc archives it is more difficult, as the primary metadata lives on the publisher’s site. The relevant series and archive information needs to be updated by the new person in charge. Unfortunately, the new person sometimes was not given instructions on how to do this, and RePEc can be of little help in maintaining information on remote sites, beyond pointing to the instructions that were given to initially build the archive. In any case, if you notice such an “bad email” message on the page of a publisher of yours, you likely know who to contact to get this fixed.
For authors, RePEc can do something. After a few months, we see whether we can change the email, either by searching our contents and the web for an alternative or by contacting recent co-authors. That has helped to keep the proportion of bad emails remarkably low, below 2%, but also means works for the RePEc team that could have been prevented if the authors maintained their contact information. However, you can help RePEc by alerting us. A list of all bad emails is here, and are marked throughout the EconPapers and IDEAS sites. We also appreciate to learn if an author died, so that we can stop trying and immortalize their profile here. Note that authors with a bad email do not count towards the rankings of their institution, the assumption being that this person has either moved or died.
NB: for editors, a bad email may come from either the publisher’s data or from the author profile, or both.
The RePEc Blog 
Would it be possible to have authors link their ORCID (http://orcid.org/) and pull email addresses (and other info) from there?
Unfortunately, ORCID requires a fee to get access to its data, and RePEc has no income to pay for that.
According to their website, the public API can be used to “Retrieve public data from a user’s ORCID record” http://members.orcid.org/api/introduction-orcid-public-api
Non-public email addresses cannot be retrieved, though. Also, they are not maintained for accuracy by ORCID, like they are by RePEc. They may still have old ones from when they used a data dump from RePEc.