Hi,

I'm running a mail server with Dovecot 2.3.20 and Apache Solr as FTS backend.

It seems that iPhone/iPad Mail clients are generating some IMAP searches, especially on header Message-ID, that are increasing our Solr I/O load, especially during the night.

Are these kind of queries normal? What are they?

You can find some logs below.

Dovecot logs:

Mar 13 21:06:14 dovecot: imap-login: Login: user=<user@domain>, method=PLAIN, rip=x.x.x.x, lip=z.z.z.z, mpid=11263, secured, session=<PQSppM32gePCBJGh>
Mar 13 21:06:14 dovecot: imap(user@domain) session=<PQSppM32gePCBJGh>: ID sent: name=iPhone Mail, version=20D67, os=iOS, os-version=16.3.1 (20D67)
Mar 13 21:06:14 dovecot: imap(user@domain) session=<PQSppM32gePCBJGh>: Disconnected: Logged out in=207 out=1128 deleted=0 expunged=0 autoexpunged=0 trashed=0 appended=0 hdr_count=0 hdr_bytes=0 body_count=0 body_bytes=0

Solr logs:

2023-03-13 21:06:14.411 INFO  (qtp1671846437-1652) [   x:dovecot] o.a.s.c.S.Request [dovecot]  webapp=/solr path=/select params={q={!lucene+q.op%3DAND}hdr:<DB8P189MB08692AE65580C36C3B7D6F53C1F59@domain6.tld>+OR+hdr:<\!\%26\!AAAAAAAAAAAYAAAAAAAAAI\/Oo\%2BConZZMkCvmEY7yWqjCgAAAEAAAAP968Yud4n1LmhwJxWgTURQBAAAAAA%3D%3D@domain5.tld>+OR+hdr:<CALEb\-gfyeQ1zJhjGKS3V8Rn3gk3byNa9co9nOU1L2BtUtKO0aw@domain7.tld>+OR+hdr:<AS4P195MB1790AA65F5F367F3CF0888BEDEA19@domain5.tld>+OR+hdr:<24E36A6E5BB2410C8090482B3E1EB40F@domain8.tld>&fl=uid,score&sort=uid+asc&fq=%2Bbox:d0f433254ee1b161c82c00002e1056c4+%2Buser:user@domain&rows=88&wt=xml} hits=0 status=0 QTime=275
2023-03-13 21:06:14.511 INFO  (qtp1671846437-1628) [   x:dovecot] o.a.s.c.S.Request [dovecot]  webapp=/solr path=/select params={q={!lucene+q.op%3DAND}hdr:<af03d59c\-2cd5\-1165\-aea5\-6ce7cfe16a89@domain.tld>+OR+hdr:<CAJbcrLvxCOGy6fcKBuhuu9B1SALwm9opS\-\-O\-kcMd3nevKrf1A@domain7.tld>+OR+hdr:<00eb01d8c8dc$caa8a580$5ff9f080$@domain1.tld>+OR+hdr:<VE1PR08MB4846DD525845DC743D47ED52EEBA9@domain7.tld>+OR+hdr:<00c701d8bb83$f307bc70$d9173550$@domain1.tld>&fl=uid,score&sort=uid+asc&fq=%2Bbox:d0f433254ee1b161c82c00002e1056c4+%2Buser:user@domain&rows=88&wt=xml} hits=0 status=0 QTime=59
2023-03-13 21:06:14.714 INFO  (qtp1671846437-1652) [   x:dovecot] o.a.s.c.S.Request [dovecot]  webapp=/solr path=/select params={q={!lucene+q.op%3DAND}hdr:<AS4P195MB179002723893D3932AF83A4CDEA29@domain5.tld>+OR+hdr:<F3112D85FDF144319FB0ABE348A75AE5@domain8.tld>+OR+hdr:<AM9PR10MB510032098A44B16182C9AAF39C4D9@domain8.tld>+OR+hdr:<\!\%26\!AAAAAAAAAAAYAAAAAAAAAI\/Oo\%2BConZZMkCvmEY7yWqjCgAAAEAAAADl2MLfkWRxJjQW\%2B3dOhZn0BAAAAAA%3D%3D@domain5.tld>+OR+hdr:<CAJbcrLtAEjLO0wbK5AAp8a3p0iRaoUeKA1wsD2ppDFeMnhL\-kA@domain7.tld>&fl=uid,score&sort=uid+asc&fq=%2Bbox:d0f433254ee1b161c82c00002e1056c4+%2Buser:user@domain&rows=88&wt=xml} hits=0 status=0 QTime=178
2023-03-13 21:06:14.771 INFO  (qtp1671846437-1628) [   x:dovecot] o.a.s.c.S.Request [dovecot]  webapp=/solr path=/select params={q={!lucene+q.op%3DAND}hdr:<DU0P189MB208990AA60E3EB5CB2F9BE98DCD39@domain>+OR+hdr:<DDA00A9A19CE4864AD87EF31B0E2113F@domain8.tld>+OR+hdr:<GV1PR01MB882049EDFF560AF4F4444F4BB1EE9@domain7.tld>&fl=uid,score&sort=uid+asc&fq=%2Bbox:d0f433254ee1b161c82c00002e1056c4+%2Buser:user@domain&rows=88&wt=xml} hits=0 status=0 QTime=34
2023-03-13 21:06:14.899 INFO  (qtp1671846437-1652) [   x:dovecot] o.a.s.c.S.Request [dovecot]  webapp=/solr path=/select params={q={!lucene+q.op%3DAND}hdr:<AS4P195MB1790922D3154E37AEF263FD1DEDF9@domain5.tld>+OR+hdr:<02E5E16DF27945B6A764F49A5D9E055E@domain8.tld>+OR+hdr:<CAEK\-5TdF_f%3Dn\%2BL1VWj3EVP9i%3DQe\%2BWaYcW%3DFNy8GSLfE5O1U7dw@domain7.tld>+OR+hdr:<4edb1720076ab71575067b0fc2b5d96c@domain2.tld>+OR+hdr:<1657012847.68884591@domain6.tld>&fl=uid,score&sort=uid+asc&fq=%2Bbox:4830f5144ee1b161c82c00002e1056c4+%2Buser:user@domain&rows=1&wt=xml} hits=0 status=0 QTime=46

Thanks

-- 
Alessio Cecchi
Postmaster @ http://www.qboxmail.it
https://www.linkedin.com/in/alessice