I made a variable 'mail_group' which appears in <dtml-var REQUEST> as: ['first last <person@here.com>','first2 last2 <person2@there.com>'] and I want to use <dtml-sendmail> so I have: <dtml-let addr="_.string.join(mail_group,',')"> <dtml-sendmail mailhost="MailHost"> To: <dtml-var addr html_quote> Subject: Feedback from somewhere from: trying@somewhere.com Comments:<dtml-var comments> </dtml-sendmail> </dtml-let> But I'm getting totally impenetrable errors: <dtml-var addr html_quote> renders perfectly to: first last <person@here.com.,first2 last2 <person2@there.com> and if I cut and paste the above line to the 'To:' field, mail is sent perfectly. BUT when i run the above sendmail script I get a page that says only: {'first': (550, '5.1.1 ... User unknown')} If there is just one name in 'mail_group' I get an even weirder page: {'f': (550, '5.1.1 ... User unknown'), 'i': (550, '5.1.1 ... User unknown'), 'r': (550, '5.1.1 ... User unknown'), 's': (550, '5.1.1 ... User unknown', 't': (550, '5.1.1 ... User unknown')} I am totally perplexed. And SUPER frustrated. Can someone tell me why this is and how to fix it if possible. thanks joshua p.s. if I use To: <dtml-in mail_group><dtml-var sequence-item><dtml-var addr html_quote><dtml-unless sequence-end>, </dtml-unless></dtml-in> I get an error like: Error Type: TypeError Error Value: len() of unsized object which I think is because of trailing spaces though I can't see any...