How do I securely send old returns to a client who has lost their returns?

[The-Tax-Lady]

Email an encrypted PDF of the return or print and mail using Priority Mail, flat rate, with tracking and delivery confirmation.

[IRonMaN]

The most secure form is to print a copy and have them stop in and pick it up.  But make sure you ask for three forms of identification.  If they don't have three forms with them, just ask to see the most reliable ID - their library card.