This shows the result of email connections from the outside world to our servers.
The light green area at the base of the chart signifies the proportion of connections from which we accept mail. All the remainder are refused for various reasons. As can be seen, there’s generally a larger proportion accepted during the working weekday than other times, but a particularly heavy spam run can either compress the green area (when we reject it) or expand it (when we accept those mails).
Currently, most of the rejects are for “technical” reasons – where the sender really isn’t playing by the rules of the various protocols. Our premium-rate customers have the capability of tuning filters specific to them; to the extent that this works in rejecting spam it would reduce the green area further. Of course, were the spam senders to reduce their efforts the green area would be much larger – so it isn’t really possible to say that either big or small is good.
conn_ref
connections refused
When one of our servers is in an overload situation. Note that many spammers deliberately send to our secondaries; we don’t really care that they crowd each-other out. Our legitimate customers are unaffected.
conn_ref_ip
too many connections from a single IP address
Some spammers open many sessions in parallel. We only accept a few.
rdns_rej
Reverse DNS verify
The name for the host found from the connecting IP address does not have an IP address listed which matches the connection.
H_rej
unacceptable HELO name
Illegal character, IP address, “localhost”, or a name which isn’t a host matching the connecting IP address.
proto_err
SMTP protocol error
Bad syntax, or not waiting for our response before sending another command.
B-rej
bounce rejection
Accounts can be marked for refusing items with an empty From address in the envelope. Such items are used for automated processing and rejection messages (“bounces”, “NDR”s) and are usually wanted, except when a spammer has picked on your name as the From for a spam run…..
condrop
connection dropped by initiator
We insert delays in the SMTP conversation when we find something suspicious. Many spammers give up.
relay_rej
attempt to relay through us
Someone who isn’t our customer asking us to send mail on their behalf.
NU_rej
no such user
a mistyped name, a spammer trying names at random, or another company checking an alleged From address with us.
SV_rej
sender verify
The senders mail host doesn’t exist, or it says the sender doesn’t exist.
V_rej
virus payload
Our virus scanner detected a known virus or phish. We will not pass these.
A_rej
administrative reject
The sender IP has recently sent a virus, or similarly annoyed us.
Q_rej
quota reject
The account is over-quota. Q-trej is a temporary quota reject.
tmp_rej
temporary reject
We couldn’t contact a mail-exchanger for the alleged From address, to check it, or user is over-quota.
noMX
From address has no mail-exchanger
The From address is totally made-up.
BCrej
Body Content reject
The message contains spam URLs or other hazardous material
Udnsbl
DNS-based blocklist
A sender is on a customer-specified blocklist – set to reject, not just warn.
Uenvl
user filter on mail envelope
Reject on source IP, From-domain or specific From address.
SVin_ok
sender verify in
Remote site checking an alleged From address with us.
in
mail accepted
We found no reason to reject (includes mark-as-spam and deliver-to-spam-folder).
Graph of Incoming Email Connections
This shows the result of email connections from the outside world to our servers.
The light green area at the base of the chart signifies the proportion of connections from which we accept mail. All the remainder are refused for various reasons. As can be seen, there’s generally a larger proportion accepted during the working weekday than other times, but a particularly heavy spam run can either compress the green area (when we reject it) or expand it (when we accept those mails).
Currently, most of the rejects are for “technical” reasons – where the sender really isn’t playing by the rules of the various protocols. Our premium-rate customers have the capability of tuning filters specific to them; to the extent that this works in rejecting spam it would reduce the green area further. Of course, were the spam senders to reduce their efforts the green area would be much larger – so it isn’t really possible to say that either big or small is good.
For enquiries about our Email services, please contact sales@tidymail.co.uk