My maddy instance can send, but cannot receive mail

[cmd410]

Describe the bug

I followed the installation tutorial, however my server can't receive mail. Outgoing mail works just fine, I've sent email to my gmail account ok, but receiving mail back was simply not possible. Google's mail delivery subsystem replied that message could not be sent due to 554 5.0.0 Internal server error (msg ID = 8647979a). Sending messages between local accounts doesn't work either, with the same logs.

Steps to reproduce

1. Attempt to send mail to maddy

Log files

Sep 10 00:20:42 maddy[919190]: smtp: incoming message        {"msg_id":"8647979a","sender":"me@gmail.com","src_host":"mail-yb1-xb33.google.com","src_ip":"[2607:f8b0:4864:20::b33]:39802"}
Sep 10 00:20:42 maddy[919190]: smtp: RCPT ok        {"msg_id":"8647979a","rcpt":"postmaster@myvps"}
Sep 10 00:20:43 maddy[919190]: smtp: DATA error        {"msg_id":"8647979a","reason":"Requested action not taken: mailbox unavailable","target":"target.lmtp"}

Configuration file

## Maddy Mail Server - default configuration file (2022-06-18)
# Suitable for small-scale deployments. Uses its own format for local users DB,
# should be managed via maddyctl utility.
#
# See tutorials at https://maddy.email for guidance on typical
# configuration changes.

# ----------------------------------------------------------------------------
# Base variables

$(hostname) = mx1.myvps
$(primary_domain) = myvps
$(local_domains) = $(primary_domain)

tls file /etc/maddy/certs/$(primary_domain)/fullchain.pem /etc/maddy/certs/$(primary_domain)/privkey.pem

# ----------------------------------------------------------------------------
# Local storage & authentication

# pass_table provides local hashed passwords storage for authentication of
# users. It can be configured to use any "table" module, in default
# configuration a table in SQLite DB is used.
# Table can be replaced to use e.g. a file for passwords. Or pass_table module
# can be replaced altogether to use some external source of credentials (e.g.
# PAM, /etc/shadow file).
#
# If table module supports it (sql_table does) - credentials can be managed
# using 'maddyctl creds' command.

auth.pass_table local_authdb {
    table sql_table {
        driver sqlite3
        dsn credentials.db
        table_name passwords
    }
}

# imapsql module stores all indexes and metadata necessary for IMAP using a
# relational database. It is used by IMAP endpoint for mailbox access and
# also by SMTP & Submission endpoints for delivery of local messages.
#
# IMAP accounts, mailboxes and all message metadata can be inspected using
# imap-* subcommands of maddyctl utility.

storage.imapsql local_mailboxes {
    driver sqlite3
    dsn imapsql.db
}

# ----------------------------------------------------------------------------
# SMTP endpoints + message routing

hostname $(hostname)

table.chain local_rewrites {
    optional_step regexp "(.+)\+(.+)@(.+)" "$1@$3"
    optional_step static {
        entry postmaster postmaster@$(primary_domain)
    }
    optional_step file /etc/maddy/aliases
}

msgpipeline local_routing {
    # Insert handling for special-purpose local domains here.
    # e.g.
    # destination lists.example.com {
    #     deliver_to lmtp tcp://127.0.0.1:8024
    # }

    destination postmaster $(local_domains) {
        modify {
            replace_rcpt &local_rewrites
        }

        deliver_to &local_mailboxes
    }

    default_destination {
        reject 550 5.1.1 "User doesn't exist"
    }
}

smtp tcp://0.0.0.0:25 {
    limits {
        # Up to 20 msgs/sec across max. 10 SMTP connections.
        all rate 20 1s
        all concurrency 10
    }

    dmarc yes
    check {
        require_mx_record
        dkim
        spf
    }

    source $(local_domains) {
        reject 501 5.1.8 "Use Submission for outgoing SMTP"
    }
    default_source {
        destination postmaster $(local_domains) {
            deliver_to &local_routing
        }
        default_destination {
            reject 550 5.1.1 "User doesn't exist"
        }
    }
}

submission tls://0.0.0.0:465 tcp://0.0.0.0:587 {
    limits {
        # Up to 50 msgs/sec across any amount of SMTP connections.
        all rate 50 1s
    }

    auth &local_authdb

    source $(local_domains) {
        check {
            authorize_sender {
                prepare_email &local_rewrites
                user_to_email identity
            }
        }

        destination postmaster $(local_domains) {
            deliver_to &local_routing
        }
        default_destination {
            modify {
                dkim $(primary_domain) $(local_domains) default
            }
            deliver_to &remote_queue
        }
    }
    default_source {
        reject 501 5.1.8 "Non-local sender domain"
    }
}

target.remote outbound_delivery {
    limits {
        # Up to 20 msgs/sec across max. 10 SMTP connections
        # for each recipient domain.
        destination rate 20 1s
        destination concurrency 10
    }
    mx_auth {
        dane
        mtasts {
            cache fs
            fs_dir mtasts_cache/
        }
        local_policy {
            min_tls_level encrypted
            min_mx_level none
        }
    }
}

target.queue remote_queue {
    target &outbound_delivery

    autogenerated_msg_domain $(primary_domain)
    bounce {
        destination postmaster $(local_domains) {
            deliver_to &local_routing
        }
        default_destination {
            reject 550 5.0.0 "Refusing to send DSNs to non-local addresses"
        }
    }
}

# ----------------------------------------------------------------------------
# IMAP endpoints

imap tls://0.0.0.0:993 tcp://0.0.0.0:143 {
    auth &local_authdb
    storage &local_mailboxes
}

Environment information

$ maddy version
0.6.2+ac4a75b linux/amd64 go1.18.2

default config: /etc/maddy/maddy.conf
default state_dir: /var/lib/maddy
default runtime_dir: /run/maddy

[cmd410]

Okay, I tested it again today and it worked. Didn't change anything really, that's a weird one.

[foxcpp]

The log message mentions target.lmtp which is not used in the configuration file you provided.

[33KK]

In case anyone else has this issue while using docker-compose: you NEED to quote the port 25, like this - "25:25", otherwise it somehow gets parsed as 1525(??)