Sparrow configuration file

This page explain about 'config.txt' file. Sparrow decide its behaviors by 'config.txt'

'config.txt' compose of plain text. Key and value is separated by white space or TAB. Each line has one settings.

Common directory

The directory that CeSMTPD uses.
By rewriting this value, the mailbox can be in an external memory.

key default value comment
HomeDir \cesmtpd\local\ Root directory of user mailbox.
TmpDir \cesmtpd\tmp\ Temporary directory that CeSMTPD uses.
QueueDir \cesmtpd\queue\ Queue directory of outgoing mail.
PopauthDir \cesmtpd\popauth\ Temporary directory of POP authentication.

Daemon schedule

CeSMTPD operates constantly regularly. The interval is specified. Units are all seconds.

key default value comment
CleanupTimer 600 Daemon check temporary files to be deleted with this timer.
SendmailRoundTimer 1200 It is an interval when mail in the queue is sent again.
QueueLifeTime 172800 It is lifetime of the mail in queue.
When this period is exceeded, the delivery of mail is given up.

POP before SMTP

As for CeSMTPD, 'POP before SMTP' option is set by default.
It is necessary to receive mail beforehand to transmit mail to the outside.
The judgment the outside domain or inside domain is done by the comparison with the domain name
set to 'Me'.

key default value comment
PopBeforeSmtp On Setting whether to use 'POP Before SMTP'.
Opposite is 'Off'.
PopAuthTimeout 1800 Validity term of POP attestation.
SMTP transmission to another domain becomes possible only in this period.

DNS servers

When SMTP is transmitted, the MX record is inquired of DNS.
It is IP address of the DNS server used in that case.
The MX record is inquired of this DNS, and mail cannot be delivered as long as it doesn't succeed.

key default value comment
1stDnsserver Must change.
When the inquiry of DNS specified with 1stDnsserver fails, the inquiry is executed to the DNS server specified with 2ndDnsserver.
2ndDnsserver @
DnsQueryTimeout 30 Timeout value when inquiring of DNS (The unit is a second. )
ParentSMTPServer @ Upper SMTP server. Comment out in default.
If set, DNS inquiry is not occured.

SMTP server

key default value comment
SMTPServers 8 Number of SMTP server threads.
SMTPPort 25 Port number of SMTP server.
me Localhost Must change.
Domain name of this host. (ex.
RcptHosts \cesmtpd\rcpthosts.txt The list of domain name to which this mail server can be received.
BadMailFrom \cesmtpd\badmailfrom.txt This list of mail address name is restricted at MAIL FROM: command.
UseSMTPAuth Yes 'Yes' enable SMTP-AUTH, 'No' disable SMTP-AUTH.
Only the CRAM-MD5 method is supported.
MaxMailSize 1024000 The size of the maximum mail (The unit is a byte) that can be received.
Default value is about 1MB.
SMTPDTimeout 300 Connection closing time. The unit is a second. Default value is 300
When it continues idle state in this term, connection is closed.


The domain name of this mail server.
Moreever, this domain is automatically given when there is no domain name in mail address.


The domain to which this SMTP server can be received.
The E-mail to the domain described here is unconditionally relayed.
Write the permitted domain name and numerical values.

example of recpthosts.txt is as follows.


It is a file to enumerate the mail address that wants to refuse at the MAIL FROM: command.

It is assumed that it was described to the list as '', the following mail addresses are refused.

If it wants to refuse in each domain, @ mark is put as follows.

The multi address input is possible by changing line.
Every time, this list is read from the file at the MAIL command. So, please note the performance at the memory and the speed when you execute it by Windows CE.


key default value comment
UseSMTPAuthPlain No Enable PLAIN authentication mechanism.
UseSMTPAuthLogin No Enable LOGIN authentication mechanism.
UseSMTPAuthCramMD5 Yes Enable CRAM-MD5 authentication mechanism.
UseSMTPAuthDigestMD5 No Enable DIGEST-MD5 authentication mechanism.

Only 'Yes' or 'No' can be used for the value.

See authentication section.

SMTP timeout

It is a time-out value when connecting it with external SMTP to deliver the external. Recommended value is provided for by RFC1123. It seems that you could decrease it to about 1/5?1/10 respectively in modern days though default value follows RFC1123.
Units are all seconds.

key default value comment
SMTPGreetingTimeout 300 Time to obtaining greeting message after it connects it.
SMTPMailTimeout 300 Time to obtaining response of Mail command.
SMTPRcptTimeout 300 Time to obtaining response of Rcpt command.
SMTPDataStartTimeout 120 Time to obtaining response of Data command.
SMTPDataBlockTimeout 180 Time to obtaining response in Mail Sending.
SMTPDataCompleteTimeout 600 Time to obtaining response of Data command end.

POP3 server

key default value comment
POP3Servers 8 Number of POP3 server threads.
POP3Port 110 Port number of POP3 server.
PasswdFile \cesmtpd\passwd.txt Path to password file.
UseAPOPOnly No 'Yes' enable APOP, 'No' disable APOP.
'PASS' command cannot use when 'Yes'.
Therefore, the only the way to authentication is APOP.

passwd file

example of passwd.txt is as follows.

john    backintheussr012
paul    yester00

It is plain text. The user name and the password are delimited with the blank or TAB.

This list is used by POP, the APOP, and the SMTP authentication.

System watermark

This is System resource watermark.
A critical error occurs when the capacity of the memory and the file on the server decreases. For instance, it not to be able to deliver the mail.
Therefore, sparrow can be stopped when falling below a certain definite value. However, Some WindowsCE become unstable when use API to acquire the capacity of the file. At such time, please set StrageWaterMark to 0. Sparrow will not check StrageWaterMark.

key default value comment
StrageWaterMark 512000 Watermark of  File system.
MemoryWaterMark 512000 Watermark of  Memory.

ILogger configuration file

key default value comment
logfilename ilog.txt Name of log file.
The full path can be specified.
logsize 10240 Size of log file.
ILogger automatically rotate the file.
This is a threshold size.
displine 200 Number of line that display on Window.
port 514 Listen port.
allowfrom IP address that permits reception.
cashsize 4096 When the cash size reaches it or when no communication continues for three seconds, then ILogger writes the log.