Problem sending email to all lists

we have access to the server mail logs.

SUCCESS (User Email) Fri 2017/03/03 01:49:36 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>michaelchaney@hotmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:36 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>melbear77@icloud.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:36 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>richie.a.russo@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>lisa.herrmann@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>lmarnold05@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>shannonpfeiffer@ymail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>angelajcrawford@hotmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>msritchey@hotmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>sashasimmons08@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>tuvok91331@aol.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>ees3@ntrs.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>stefanie.letcher@phoenix.gov] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>cbemis27@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:37 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>piorkowski.ben@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>stephbader@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>jamieesprout@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>tashina_atine@yahoo.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>quinton.jones@talkmobilenet.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>rebecca@bluecloudcreative.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>garthgold@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>junga_1@yahoo.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>eric.wong@talkmobilenet.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>dwturner@asu.edu] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:38 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>shijej@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:39 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>pamozsoy898@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:39 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>wfy8826907719@sing.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:39 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>roxannedlr@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]
SUCCESS (User Email) Fri 2017/03/03 01:49:39 UTC Club:[4630] From:[info@downtoearthtoastmasters.com (DTE Email Account)] To:[guests-4630@toastmastersclubs.org>jarondruyon@gmail.com] CC:[] Subject:[You're invited: Down to Earth Toastmasters is turning 20!]

Do the server logs also indicate that the email was sent to all of the prospects, former member, and member emails--along with the rest of the guest emails (the list you provided lists only about half of them)? Could it just be taking awhile for everything to process? Or could the server have gotten hung up and stopped sending? I could try to resend to all of the emails except the ones you listed.

The emails still hadn't come through to my member email account or my husband's email account by this morning, so I resent the email to all of the lists. I took out the offending email address on the guest list (rockchalkph@gmail.com) in case the problem was that the server got hung up on this email. I also sent four separate emails (members, former members, guests, prospects) instead of sending one email to all of the lists in case the problem was that the server was overloaded by sending to so many email addresses at once. It seems to have worked this time!