- - Message queue
create table MAIL_MESSAGE_QUEUE (
    MQ_ID               varchar,    - - FK MAIL_MESSAGE (MM_ID)
    MQ_RECIEVER         varchar,    - - foreign mail exchanger
    primary key (MQ_ID))


-- Mail Table
create table DB.DBA.MAIL_MESSAGE (
    MM_ID               integer,        -- Unique id of message (per user)
    MM_OWN      varchar (128),  -- Local WebDAV account (recipient, mail box owner) name,
                                        FK references WS.WS.SYS_DAV_USER (U_NAME)
    MM_FLD      varchar (128), -- Message Folder (initial 'Inbox')
    MM_FROM     varchar (512),          -- From: RFC822 header field
    MM_TO               varchar (512),          -- To: RFC822 header field
    MM_CC               varchar (512),          -- Cc: RFC822 header field
    MM_BCC      varchar (512),  -- Bcc: RFC822 header field
    MM_SUBJ     varchar (512),  -- Subject of the message
    MM_REC_DATE varchar (50),   -- Date of arrival
    MM_SND_TIME varchar (50),   -- Date of posting
    MM_IS_READED        integer,                -- Read flag (0/1 not read, 1 - read)
    MM_BODY     long varchar,   -- Message content (including message header)
    primary key (MM_OWN, MM_FLD, MM_ID)
[Note] Note:

MM_FROM, MM_TO, MM_CC, MM_BCC, MM_SUBJ, MM_SND_TIME exists only if there exists corresponding RFC822 headers in mail message

-- Temporary message MIME parts table (for message composition)
create table DB.DBA.MAIL_PARTS (
    MP_ID       integer,                -- Unique id per user (order of parts)
    MP_PART     long varbinary, -- Message MIME part body
    MP_ATTRS    long varbinary, -- Message MIME part attributes
    MP_OWN      varchar (128),  -- WebDAV user name - FK REFERENCES WS.WS.SYS_DAV_USER (U_NAME)
    primary key (MP_OWN, MP_ID)

- - Local mail users
(this table will be needed only in case of different DB, DAV and MAIL users)
create table MAIL_USERS (
    MU_NAME     varchar,
    MU_PWD      varchar,
    primary key (MU_NAME))

- - Allowed relay domains
(only in case of allowed relaying)
create table MAIL_RELAY (
    MR_ALLOWED  varchar;
    primary key (MR_ALLOWED))