Which email addresses should be used for issuances?
The email address should be for the specific stakeholder even if they do not check their email frequently.
At the very least, it needs to be the email address of an individual who has power-of-attorney to receive legal documents on behalf of the security holder. If this is the case, then the company should have verification of the power-of-attorney before they send out any securities.
If the security holder is a minor (under the age of 18), then the email address used should be that of the minor's legal guardian.