Migrate email password from a DB

Hello, I made a script to migrate hundreds of emails from a server without cpanels. Everything works perfectly but I have some problem to migrate psw from the old server. Passwords are stored in a DB with this format: {PLAIN-MD5}d288d36da48c345f31cdff90fd141bb2
I thought it would be enough to import this psw into the shadow file with the format: $1$d288d36da48c345f31cdff90fd141bb2
Any advice? Is it possible?