Secretary succession

What the secretary's office actually holds

Under Robert's Rules, the secretary is the recording officer and the custodian of the organization's records, except whatever the bylaws specifically assign to someone else. That includes the minute book, correspondence, and notices sent to members. A resignation email and a few forwarded messages are not a handoff; the actual files are.

"the recording officer of the assembly and the custodian of it's records except such as are specifically assigned to others"

Source: Robert's Rules of Order, "The Officers and the Minutes", Henry M. Robert (1915 public domain edition)

Who fills the vacancy

Do not assume the board can simply appoint a new secretary. Robert's Rules gives that authority to whichever body elected the secretary in the first place, unless the bylaws give the board full authority to act between meetings. Check your bylaws for who elects the secretary and whether the board has been given power to fill vacancies between meetings; the answer differs by association.

What minutes do not capture

A new secretary who reads the minute book expecting to find the reasoning behind past decisions will not find it there. Minutes record what the board did, not what was said or why.

"Minutes are a record of what was done at a meeting, not a record of what was said."

Source: Robert's Rules of Order Official Website, Frequently Asked Questions, Robert's Rules Association

That gap is why a decision log exists as a separate document from the minutes. Nobody is required to keep one, but a board that skips it hands its successors decisions with the reasoning stripped out.

How long the records have to survive

Retention rules for minutes and correspondence come from state statute where one exists, and from your bylaws where it does not. Florida requires minutes of board and member meetings to be kept for at least seven years. California defines minutes as an association record subject to member inspection and separately requires election materials to be kept for at least one year. Retention periods and covered categories differ by state; confirm your own state's requirement before setting a retention policy.