Hi! I am unable to send base64 encoded attachments in Slackware 10.0 (a fresh install). I have tried this in Kmail 1.7 and using browsers (Firefox & Konqueror) to access my on line webmail account. Both of these methods access the same ISP. In addition, I can receive base64 encoded attachments in Kmail and they are decoded appropriately. It appears that the email with attachment starts to send and the server stops responding and eventually times out. This same PC has a WinXP partition that I can send the same attachment via IE and the webmail interface but I don't have an mail client installed so this made me think it's probably not an ISP problem but a linux issue larger than just Kmail.

Any ideas on this would be most helpful!

I contacted my ISP an he offered the expected "best of luck." I'm not intimately familiar with kernel options but the fact that both the browser interface and two email clients fail makes me wonder what they have in common...kernel? I am using a custom 2.6.7 kernel...I may try to boot the default 2.4.2x that comes with Slack10.0 and see if I can send then. Are there kernel options that might effect an email attachment?

Thanks.

More thoughts...what about PPP setup or modem?

Ok, some success! I started reading alot about pppd and the MTU setting. Reducing this to 542 (from 1500) seems to help. I was able to send both via the web interface and kmail. I edited my /etc/ppp/options and it appears that ifconfig ppp0 mtu 542 (or whatever number) allows you to change the MTU setting on the fly. The ifconfig did not seem to update my options file so I did that by hand.

So, how can I optimize my MTU value...lower works but it seems I should try to keep it as high as possilbe?

Thanks