SMTP problems

[GavinHRC]

For the last couple of weeks I've had trouble sending mail with even the smallest, less than 100KB, attachment. It makes no difference which SMTP server I use, gmail or iburst, it just times out. Eventually the mail goes, normally after trying for about an hour. Browsing and downloading are working fine, I can upload via ftp, everythings ok just SMTP? I've changed the server time out settings, no difference.

 

[r00igev@@r]

For the last couple of weeks I've had trouble sending mail with even the smallest, less than 100KB, attachment. It makes no difference which SMTP server I use, gmail or iburst, it just times out. Eventually the mail goes, normally after trying for about an hour. Browsing and downloading are working fine, I can upload via ftp, everythings ok just SMTP? I've changed the server time out settings, no difference.

Please forward me your UTID via PM and I'll have it investigated.

 

[<?php?>]

Have you removed / deleted the e-mail account and re-added the account in the e-mail client? I had a similar problem when I still used Outlook. You can also check your MTU settings.

http://en.wikipedia.org/wiki/Maximum_transmission_unit

In computer networking, the maximum transmission unit (MTU) of a communications protocol of a layer is the size (in bytes) of the largest protocol data unit that the layer can pass onwards. MTU parameters usually appear in association with a communications interface (NIC, serial port, etc.). Standards (Ethernet, for example) can fix the size of an MTU; or systems (such as point-to-point serial links) may decide MTU at connect time.

A larger MTU brings greater efficiency because each packet carries more user data while protocol overheads, such as headers or underlying per-packet delays, remain fixed; the resulting higher efficiency means a slight improvement in bulk protocol throughput. A larger MTU also means processing of fewer packets for the same amount of data. In some systems, per-packet-processing can be a critical performance limitation.

Large packets can occupy a slow link for some time, causing greater delays to following packets and increasing lag and minimum latency. For example, a 1500-byte packet, the largest allowed by Ethernet at the network layer (and hence over most of the Internet), ties up a 14.4k modem for about one second.

Large packets are also problematic in the presence of communications errors. Corruption of a single bit in a packet requires that the entire packet be retransmitted. At a given bit error rate larger packets are more likely to be corrupted. Retransmissions of a larger packet takes longer.

 

[GavinHRC]

Have you removed / deleted the e-mail account and re-added the account in the e-mail client? I had a similar problem when I still used Outlook. You can also check your MTU settings.

http://en.wikipedia.org/wiki/Maximum_transmission_unit

Thanks, I tried adding another email account, same problem, but I discovered it is all uploads not just SMTP, I've pm'd Ronald. Been with iBurst many years so I'm familiar with MTU.