hub/email: do not send email again, if successfully sent in last week
hub/email: do not send email again, if successfully sent in last week

tscholl2/smc,tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,DrXyzzy/smc,sagemathinc/smc,sagemathinc/smc,sagemathinc/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,DrXyzzy/smc,DrXyzzy/smc