Have you ever experienced this? Either no e-mail can reach you within a rather long period of time, or the same one keeps bombarding your e-mail account several times a day? One of the causes for such phenomena is that the e-mail network was jammed with e-mail of large file size, and thus traffic congestion or server malfunction results.

The staff e-mail servers failed quite often some time ago and investigation found that some users had repeatedly sent out some AVI video files and MP3 music files of over 5MB each. Large files are NEVER encouraged to be sent via e-mail because:

1. servers will be overloaded,

2. server storage will be used up,

3. e-mail may be re-sent at regular intervals due to time-out or retries, and

4. e-mail may be bounced back as it exceeds the limit of the recipient's mail server, which causes serious traffic congestion on the way back.

All these will cause very slow or sluggish e-mail delivery, if the e-mail can ever be sent. Therefore, all colleagues are strongly recommended to follow the guidelines below to ensure the smooth flow of e-mail transfer:

1. avoid sending oversized e-mail (2MB or less if it is for external parties),

2. for e-mail of size more than 5MB, use FTP service or put it on the Web for retrieval, and

3. for broadcasting, the e-mail should be short and small in size, and if possible send Web links instead of file attachments.