Since SeaMonkey German 2.39b1 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:42.0 from official download area) Gecko/20100101 Firefox/42.0 Build 20151028234211 (Classic Theme) on German WIN7 64bit after every launch of SM e-mail-client I get a message "Alert: There are non-Ascii characters in the local part of the recipient. This is not yet supported. Please change this address and try again". The bad with this alert is that it does not tell where I can find the complained e-mail-address; for my various activities I have 20 e-mail-accounts in SeaMonkey. Because this message does not appear if I reject "Send Later" request to send e-mails now, I think reason for this alert is an e-mail with improper recipient address. But who can know? So I recommend to add to the alert: * Address-book or e-mail account + folder * e-mail-address itself This one seems related to "Bug 1200050 - there are non-ascii characters in the local part of the recipient address when empty email in address book" Probably a mail-core issue