dovecot-sieve help

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hi,
 I have a question  hope to get everybody's help, thank you.
I write the dovecot sieve rules, use notify:mailto. such as 
mailto:mym...@dovecot.org, this is ok.but i want to go to a url address,like 
this,mailto:"http://http://wiki.dovecot.org/".but i don't know how to do it.I 
hope you can help me.thanks.