If you change the email address, make sure to 1) set up autoforwarding, 2) announce the change to all your contacts so that they can update their records.

I still think that you can go it without changing the email address, because lots of your contacts have your email address and it is a nuisance to change/forward/update etc. Not IMPOSSIBLE, but a NUISANCE.

So if you want to really cut to the chase, you need to write to her stating that your policy on suicidal letters stipulates that such letters be forwarded to the local police department of the sender, out of concern for the sender's safety. Say that to the extent that her most recent communication did not mention an immediate threat to her existence, you would not forward it to the police department, but, "going forward", as they say, you will not make any exceptions to your policy on suicidal letters. Period.

Since she is engaging in emotional blackmail (thanks Bill for the right terminology), it is only fair to be a little harsh in response.

best!