[Gmail-Users] gmail sender header makes custom from address useless

yes!
I agree with
http://pascal.vanhecke.info/2005/08/31/gmail-sender-header-makes-custom-from-address-useless-for-mailinglists/

"outlook 2003 treats the Sender: as the real sender "on behalf of" the From:"

"Mailing list software like ezmlm also take this sender header into account when checking membership"

"I hope they modify the system to replace Sender: with something far less intrusive like X-Googlemail-Userid: which would both preserve the identifiable gmail account information (making abuse complaints far easier to manage) and put the customized domain back up front and center."