Message blob storage

Some IMAP storage backends support pluggable message storage that allows message contents to be stored separately from IMAP index.

Modules described in this page are what can be used with such storage backends. In most cases they have to be specified using the 'msg_store' directive, like this:

storage.imapsql local_mailboxes {
    msg_store fs /var/lib/email

Unless explicitly configured, storage backends with pluggable storage will store messages in state_dir/messages (e.g. /var/lib/maddy/messages) FS directory.

FS directory storage (storage.blob.fs)

This module stores message bodies in a file system directory.

storage.blob.fs {
    root <directory>
storage.blob.fs <directory>

Configuration directives

Syntax: root path
Default: not set

Path to the FS directory. Must be readable and writable by the server process. If it does not exist - it will be created (parent directory should be writable for this). Relative paths are interpreted relatively to server state directory.

Amazon S3 storage (storage.blob.s3)

This modules stores messages bodies in a bucket on S3-compatible storage.

storage.blob.s3 {
    secure yes
    access_key "Q3AM3UQ867SPQQA43P2F"
    secret_key "zuf+tfteSlswRu7BJ86wekitnifILbZam1KYY3TG"
    bucket maddy-test

    # optional
    region eu-central-1
    object_prefix maddy/


storage.imapsql local_mailboxes {
    msg_store s3 {
        access_key "..."
        secret_key "..."
        bucket maddy-messages
        region us-west-2

Configuration directives

Syntax: endpoint _address:port_


Root S3 endpoint. e.g.

Syntax: secure boolean
Default: yes

Whether TLS should be used.

Syntax: access_key string
Syntax: secret_key _string_


Static S3 credentials.

Syntax: bucket _name_


S3 bucket name. The bucket must exist and be read-writable.

Syntax: region string
Default: not set

S3 bucket location. May be called "endpoint" in some manuals.

Syntax: object_prefix string
Default: empty string

String to add to all keys stored by maddy.

Can be useful when S3 is used as a file system.