here is the dovecot sieve log for an email that never showed up under the schedule user account, and the dovecot log doesn't have anything for this user at that timestamp.
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Loading modules from directory: /usr/lib64/dovecot
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Module loaded: /usr/lib64/dovecot/lib01_acl_plugin.so
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Module loaded: /usr/lib64/dovecot/lib10_quota_plugin.so
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Module loaded: /usr/lib64/dovecot/lib20_mailbox_alias_plugin.so
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Module loaded: /usr/lib64/dovecot/lib90_sieve_plugin.so
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: auth USER input: schedule@xxxxxx.xxx home=/var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18/ quota_rule=*:bytes=10485760000
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Added userdb setting: plugin/quota_rule=*:bytes=10485760000
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Effective uid=2000, gid=2000, home=/var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18/
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota root: name=user backend=dict args=:proxy::quotadict
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota rule: root=user mailbox=* bytes=10485760000 messages=0
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota warning: bytes=10485760000 (100%) messages=0 reverse=no command=quota-warning 100 schedule@xxxxxx.xxx
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota warning: bytes=9961472000 (95%) messages=0 reverse=no command=quota-warning 95 schedule@xxxxxx.xxx
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota warning: bytes=9437184000 (90%) messages=0 reverse=no command=quota-warning 90 schedule@xxxxxx.xxx
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota warning: bytes=8912896000 (85%) messages=0 reverse=no command=quota-warning 85 schedule@xxxxxx.xxx
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota grace: root=user bytes=1048576000 (10%)
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: dict quota: user=schedule@xxxxxx.xxx, uri=proxy::quotadict, noenforcing=0
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Namespace : type=private, prefix=, sep=/, inbox=yes, hidden=no, list=yes, subscriptions=yes location=maildir:/var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18//Maildir/:INDEX=/var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18//Maildir/
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: maildir++: root=/var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18//Maildir, index=, indexpvt=, control=, inbox=/var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18//Maildir, alt=
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: acl: initializing backend with data: vfile
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: acl: acl username = schedule@xxxxxx.xxx
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: acl: owner = 1
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: acl vfile: Global ACLs disabled
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Namespace : type=shared, prefix=Shared/%u/, sep=/, inbox=no, hidden=no, list=children, subscriptions=yes location=maildir:%Lh/Maildir/:INDEX=%Lh/Maildir/Shared/%u
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: shared: root=/var/run/dovecot, index=, indexpvt=, control=, inbox=, alt=
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: acl: initializing backend with data: vfile
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: acl: acl username = schedule@xxxxxx.xxx
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: acl: owner = 0
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: acl vfile: Global ACLs disabled
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: quota: quota_over_flag check: quota_over_script unset - skipping
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota root: name=user backend=dict args=:proxy::quotadict
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota rule: root=user mailbox=* bytes=1073741824 messages=0
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota warning: bytes=1073741824 (100%) messages=0 reverse=no command=quota-warning 100 raw mail user
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota warning: bytes=1020054732 (95%) messages=0 reverse=no command=quota-warning 95 raw mail user
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota warning: bytes=966367641 (90%) messages=0 reverse=no command=quota-warning 90 raw mail user
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota warning: bytes=912680550 (85%) messages=0 reverse=no command=quota-warning 85 raw mail user
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Quota grace: root=user bytes=107374182 (10%)
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: dict quota: user=raw mail user, uri=proxy::quotadict, noenforcing=0
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: none: root=, index=, indexpvt=, control=, inbox=, alt=
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: quota: quota_over_flag check: quota_over_script unset - skipping
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Destination address: schedule@xxxxxx.xxx (source: user@hostname)
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: Pigeonhole version 0.4.20 (7cd71ba) initializing
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: file storage: Storage path `/var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18//sieve' not found
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: file storage: Failed to normalize active script directory (path=/var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18//sieve): Part of the path does not exist (yet)
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: file storage: Using Sieve script path: /var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18//sieve/dovecot.sieve
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: file storage: Storage path `/var/vmail/vmail1/xxxxxx.xxx/s/c/h/schedule-2018.11.08.15.33.18//sieve/dovecot.sieve' not found
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: storage: No default script location configured
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: User has no personal script
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: file storage: Using Sieve script path: /var/vmail/sieve/dovecot.sieve
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: file script: Opened script `dovecot' from `/var/vmail/sieve/dovecot.sieve'
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: Executed before user's personal Sieve script(1): /var/vmail/sieve/dovecot.sieve
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Mailbox stdin: Opened mail UID=1 because: header Message-ID (Cache file is unusable)
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: Opening script 1 of 1 from `/var/vmail/sieve/dovecot.sieve'
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: Loading script /var/vmail/sieve/dovecot.sieve
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: Script binary /var/vmail/sieve/dovecot.svbin successfully loaded
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: binary save: not saving binary /var/vmail/sieve/dovecot.svbin, because it is already stored
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: sieve: Executing script from `/var/vmail/sieve/dovecot.svbin'
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Mailbox stdin: Opened mail UID=1 because: header X-Spam-Flag (Cache file is unusable)
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: INBOX: Mailbox opened because: lib-lda delivery
Dec 03 13:06:09 lda(schedule@xxxxxx.xxx): Debug: Mailbox stdin: Opened mail UID=1 because: copying
the mail log below shows it come in, in which the email was to both schedule and Lorenzo, but only Lorenzo received the email and the email cannot be found on the server at all.
Dec 3 13:06:07 mx postfix/smtpd[8997]: connect from mail-eopbgr1390138.outbound.protection.outlook.com[40.107.139.138]
Dec 3 13:06:08 mx postfix/smtpd[8997]: A83A08161045: client=mail-eopbgr1390138.outbound.protection.outlook.com[40.107.139.138]
Dec 3 13:06:09 mx postfix/cleanup[9017]: A83A08161045: message-id=<3A3359C5-068C-45CF-8173-8328106D37D8@xxxxxx.xxx>
Dec 3 13:06:09 mx postfix/qmgr[27333]: A83A08161045: from=<richard@xxxxxx.xxx>, size=5863, nrcpt=2 (queue active)
Dec 3 13:06:09 mx clamd[1767]: SelfCheck: Database status OK.
Dec 3 13:06:09 mx postfix/smtpd[8997]: disconnect from mail-eopbgr1390138.outbound.protection.outlook.com[40.107.139.138]
Dec 3 13:06:09 mx postfix/smtpd[9028]: connect from mx.diamondplumbingtexas.com[127.0.0.1]
Dec 3 13:06:09 mx postfix/smtpd[9028]: 9DCB28171891: client=mx.diamondplumbingtexas.com[127.0.0.1]
Dec 3 13:06:09 mx postfix/cleanup[9017]: 9DCB28171891: message-id=<3A3359C5-068C-45CF-8173-8328106D37D8@xxxxxx.xxx>
Dec 3 13:06:09 mx postfix/qmgr[27333]: 9DCB28171891: from=<richard@xxxxxx.xxx>, size=6634, nrcpt=2 (queue active)
Dec 3 13:06:09 mx postfix/smtpd[9028]: disconnect from mx.diamondplumbingtexas.com[127.0.0.1]
Dec 3 13:06:09 mx amavis[1192]: (01192-18) Passed CLEAN {RelayedInbound}, [40.107.139.138]:6126 [40.107.139.138] <richard@xxxxxx.xxx> -> <lorenzo@xxxxxx.xxx>,<schedule@xxxxxx.xxx>, Queue-ID: A83A08161045, Message-ID: <3A3359C5-068C-45CF-8173-8328106D37D8@xxxxxx.xxx>, mail_id: KmDf5hoBfiFE, Hits: -, size: 5856, queued_as: 9DCB28171891, dkim_sd=selector1-xxxxxxx-com:xxxxxxxxxx.onmicrosoft.com, 363 ms
Dec 3 13:06:09 mx postfix/smtp[9025]: A83A08161045: to=<lorenzo@xxxxxx.xxx>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.1, delays=0.72/0.01/0/0.38, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10025): 250 2.0.0 Ok: queued as 9DCB28171891)
Dec 3 13:06:09 mx postfix/smtp[9025]: A83A08161045: to=<schedule@xxxxxx.xxx>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.1, delays=0.72/0.01/0/0.38, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10025): 250 2.0.0 Ok: queued as 9DCB28171891)
Dec 3 13:06:09 mx postfix/qmgr[27333]: A83A08161045: removed
Dec 3 13:06:09 mx postfix/pipe[9030]: 9DCB28171891: to=<schedule@xxxxxx.xxx>, relay=dovecot, delay=0.33, delays=0.03/0.02/0/0.28, dsn=2.0.0, status=sent (delivered via dovecot service)
Dec 3 13:06:10 mx postfix/pipe[9029]: 9DCB28171891: to=<lorenzo@xxxxxx.xxx>, relay=dovecot, delay=0.36, delays=0.03/0.01/0/0.32, dsn=2.0.0, status=sent (delivered via dovecot service)
Dec 3 13:06:10 mx postfix/qmgr[27333]: 9DCB28171891: removed