InterKan.Net Email Policies

Limits/Storage | SMTP AuthSpamBlackhole ListAnti-VirusUnsafe ExtensionsMultipart EmailsSuspicious Characters | Forward Email

Limits & Storage

Message Limits

Incoming and outgoing messages have the following limits:

  • Maximum of 50 total recipients per message (including TO, CC, and BCC);
  • Maximum size of 20 MB per email (search "email large file" for alternatives);
  • Maximum number of outgoing messages is 500 or 250 MB per day per account (whichever is greater).

Inbox Storage

IKN enforces the following inbox rules on our servers:

  • Mail box size may not exceed a total of 75 MB;
  • All messages over 90 days old will be removed;
  • Read messages over 21 days old will be removed;
  • Messages over 30 days old in suspended or disabled accounts will be removed.

This affects ONLY messages on the server in the inbox. Mail already downloaded to a PC or kept elsewhere on the server, such as in Webmail, will be left untouched.

Outbound (SMTP) Mail Servers Require Authentication

This reduces the number of spam and virus emails originating from our customers. Most Internet Service Providers have adopted this practice to reduce spam. We must take this action to ensure that a few bulk emailers do not get InterKan.Net blacklisted from sending mail to other Internet Service Providers.

Unsolicited Commercial Email (Spam)

Our mail server scans all incoming messages for UCE or Spam. We scan and label all messages using over 150 tests in order to determine a message's "Spam score." The higher the score, the more likely it is UCE.

By default, we only reject messages that reach a certain score or higher. To avoid mistakenly identifying legitimate messages, our threshold is set to insure a lower false positive rate while eliminating the majority of all UCE. If a message is determined to be UCE, it is rejected and returned to the sender whenever possible. If a message is just suspected to be spam but the server is not confident enough to reject it, the subject is just changed to begin with ***SPAM*** and/or has a spam report text file attached to help further troubleshoot.

However, no system is perfect. So if you believe your message has mistakenly been labeled as UCE, please notify IKN Postmaster. We can offer you information as to what triggered the label.

Also see Real-Time Blackhole List (RBL) below.

Real-Time Blackhole List (for UCE)

Our mail server utilizes Real-Time Blackhole Lists (RBLs) to block known spammers and open-relays. If your email server has been rejected, you must contact your administrator or postmaster to correct the problem.

If you are rejected because you are running your own mail server on a dial-up, cable, or DSL service, then you should utilize or route all mail first to your ISP's SMTP for outgoing mail.


Our mail server scans all incoming and outgoing messages for viruses. Any message found to contain a virus is dropped without notice.

If you received a rejection notice from IKN, most likely it is a scam or a virus itself since we do not send such notices. When in doubt, please call us and always insure you are running the latest versions of anti-virus software such as:

Be sure to regularly update your anti-virus software with the latest virus definitions.

Unsafe File Extensions

Our mail server rejects messages that contain unsafe files that can be used to hide computer viruses.

See the list of file types below.

If you received a rejection message, we ask that you arrange an alternative means of receiving the file such as renaming the file's extension or zipping (compressing) the file before attaching it to the message.

It is up to the sender in this situation; otherwise further unsafe files will continue to be rejected.

List as posted by Microsoft at

File ExtensionDescription
ADE Microsoft Access project extension
ADP Microsoft Access project
ASX Windows Media Audio / Video
BAS Microsoft Visual Basic class module
BAT Batch file
CHM Compiled HTML Help file
CMD Microsoft Windows NT Command script
COM Microsoft MS-DOS program
CPL Control Panel extension
CRT Security certificate
EXE Executable file format (program)
HLP Help file
HTA HTML program
INF Setup Information
INS Internet Naming Service
ISP Internet Communication settings
JAR Extended from. ZIP. A JAR (Java ARchive)
JS JScript File
JSE JScript Encoded Script file
LNK Shortcut
MDA Microsoft Access add-in program
MDE Microsoft Access MDE database
MDT Microsoft Access workgroup information
MDW Microsoft Access workgroup information
MDZ Microsoft Access wizard program
MSI Microsoft Windows Installer package
MSP Microsoft Windows Installer patch
MST Microsoft Windows Installer transform,
Microsoft Visual Test source file
OPS Office XP settings
PCD Photo CD Image, Microsoft Visual compiled script
PIF Shortcut to MS-DOS program
PRF Microsoft Outlook profile settings
REG Registration entries
SCF Windows Explorer command
SCR Screen saver
SCT Windows Script Component
SHB Shell Scrap object
SHS Shell Scrap object
VB VBScript file
VBE VBScript Encoded script file
VBS VBScript file
WSC Windows Script Component
WSF Windows Script file
WSH Windows Scripting Host Settings file

Multipart Emails / Attachments

Our mail server rejects multipart emails and attachments as they constitute a security hazard. Multipart messages bypass the normal anti-virus and anti-spam system by breaking up the message into parts and sending them separately. This makes it difficult if not impossible to scan.

If an attachment is larger than our restricted size, please contact the sender and arrange an alternate means of receiving it (i.e. web or FTP download).

Suspicious Characters

Our mail server rejects messages that contain illegal characters that can be used to hide computer viruses. This is usually caused by an improperly configured program on the computer system that sent the email.

All Internet activity is governed by Requests for Comments (RFC's) published by The Internet Society. Rules for email are contained in RFC 2821 and RFC 2822, located at:

Forwarding Email

We are glad to forward email to other addresses for you at no charge while you have an account with us.