Legal Question in Wills and Trusts in California

Generally, absent specific terms to the contrary in a particular transaction, the "mailbox rule" is that an action taken by mail is effective when deposited in the mail. The law school example is where A offers in writing to sell Blackacre to B for $100,000 on Sunday. A mails his acceptance to B on Monday. On Monday afternoon C tells A she will pay $200,000 for Blackacre. Tuesday morning before receiving the acceptance from A, B hand delivers a written rescission of the offer to A. The rescission is too late; A can enforce the contract.

That said, however, there may be specific rules in IRA account documents that differ.