Why is it that many yahoogroup mails do not reach my gmail address even for groups of which I am a moderator?

My account settings are for individual mails to be delivered into my inbox. Yahoogroups list the gmail address as current; it is not bouncing mails. The missing messages are not in my spam mailbox. All mails are being delivered, without problem, to my office e-mail address, which is also on the group mailing list.