Question
Why do different email accounts on my server have different file structure?
Answer
The server can use two different types of storage systems for email on the server - mdbox and maildir. If you have migrated one account from another it's possible it was using a different storage format, and the files will look different on the server. Here is an example of the file structure in /home/username/mail/domain.com/email with both MDBox and Maildir:
MDBox:
/home/usename/mail/domain.com/email]cPs# ll
total 116
-rw-r----- 1 username username 0 Feb 5 2018 dovecot-acl-list
-rw-r----- 1 username username 1136 Feb 1 2019 dovecot.index
-rw-r----- 1 username username 64980 Feb 6 2019 dovecot.index.cache
-rw-r----- 1 username username 4372 Feb 6 2019 dovecot.index.log
-rw-r----- 1 username username 1024 Aug 27 23:04 dovecot.list.index
-rw-r----- 1 username username 1944 Aug 28 11:03 dovecot.list.index.log
-rw-r----- 1 username username 72 Apr 4 2019 dovecot.mailbox.log
-rw-r----- 1 username username 53 Aug 28 11:03 dovecot-quota
-rw-r----- 1 username username 7614 Feb 6 2019 dovecot-uidlist
-rw-r----- 1 username username 8 Apr 4 2019 dovecot-uidvalidity
-rw-r----- 1 username username 0 Nov 27 2017 dovecot-uidvalidity.5a1c0c01
drwxr-x--x 9 username username 97 Apr 4 2019 mailboxes
-rw-r----- 1 username username 5 Feb 6 2019 mailbox_format.cpanel
-rw------- 1 username username 2049 Feb 6 2019 maildirsize
drwxr-x--x 2 username username 177 Aug 28 07:29 storage
-rw-r----- 1 username username 18 Apr 4 2019 subscriptions
Maildir:
/home/username/mail/domain.com/email]# ll
total 72
drwxr-x--x 11 username username 4096 Jul 17 10:17 ./
drwxr-x--x 3 username username 4096 May 9 2018 ../
drwxr-x--x 5 username username 4096 Jul 17 10:17 .Archive/
drwxr-x--x 2 username username 4096 May 9 2018 cur/
-rw-r----- 1 username username 0 Jul 17 10:17 dovecot-acl-list
-rw-r----- 1 username username 160 Jul 17 10:17 dovecot.index.log
-rw-r----- 1 username username 2396 Jul 17 10:17 dovecot.list.index.log
-rw-r----- 1 username username 48 Jul 17 10:17 dovecot.mailbox.log
-rw-r----- 1 username username 51 Jul 17 10:17 dovecot-uidlist
-rw-r----- 1 username username 8 Jul 17 10:17 dovecot-uidvalidity
-r--r--r-- 1 username username 0 May 13 2019 dovecot-uidvalidity.5cd9cd10
drwxr-x--x 5 username username 4096 Jul 17 10:17 .Drafts/
drwxr-x--x 5 username username 4096 May 13 2019 .Junk/
-rw------- 1 username username 18 May 9 2018 maildirsize
drwxr-x--x 2 username username 4096 May 9 2018 new/
drwxr-x--x 5 username username 4096 Jul 17 10:17 .Sent/
drwxr-x--x 5 username username 4096 Jul 17 10:17 .spam/
-rw-r----- 1 username username 18 Jul 17 10:17 subscriptions
drwxr-x--x 2 username username 4096 Jul 17 10:17 tmp/
drwxr-x--x 5 username username 4096 Jul 17 10:17 .Trash/