421 Too many SMTP sessions for this host

This is not the message I wanted to get after sending an important e-mail to a supplier in Taiwan. To make things worse, this isn’t a message I received when connecting to my (e-mail) provider’s mail server. Instead, the mail server itself received this message when trying to relay my e-mail to Hinet, where my supplier has his account. Maybe somebody at Hinet had a brilliant idea of how to reduce SPAM (“let’s not accept more than 8 e-mails per month from other mail servers”) or their server was having temporary problems and nobody could be bothered to check if the error message sent together with error code 421 made sense. In any case, my e-mail wasn’t getting through.

Other than sending a fax, the solution I found was to connect directly to the mail server at Hinet (ms12a.hinet.net) from my e-mail software, thereby bypassing my provider’s mail server. On this illustration from Wikipedia, this would mean drawing an arrow from “Alice’s MUA” directly to “mx.b.org”. My first attempt failed (“relaying denied”) because I had forgotten to remove my own address from the BCC field. Since Hinet’s server (at least this one) isn’t an open relay, it only accepts e-mails for its own users (*@hinet.net). After I fixed this, sending the e-mail was no problem (and it actually arrived, too).

Luckily, it was easy to add an alternative mail server in my e-mail software (Becky!). Still, this wasn’t the first time I had experienced problems communicating with business partners in Taiwan who were using Hinet and I’m sure I’m not the only one. I’m really wondering how many potential deals were never concluded because of Hinet’s poor performance.

Corrupted ZIP file?

I was very happy today to discover that one of our suppliers had high-resolution product images available for download. Since taking good product pictures is not done in a snap, this had the potential to save me lots of time. Unfortunately, after downloading the 30MB ZIP I received the following error message when trying to open it: “The Compressed (zipped) Folder is invalid or corrupted”. Downloading the file again didn’t make a difference. Sure, I could’ve asked the supplier to provide me with an uncorrupted file, but I knew this would take a while.

That’s why I went looking for software which might be able to fix the ZIP file. I quickly found two affordable programs: Zip Repair Pro and Advanced Zip Repair. Unfortunately, the trial version of Zip Repair Pro only repairs files up to 5 MB. Not wanting to spend 29,95 US$ to find out whether or not the ZIP file could be repaired, I gave Advance Zip Repair a try. This software uses a different approach: It will try to repair the file and show a report, but it won’t output the fixed file unless you register (29,95 US$). Repairing the ZIP file I had downloaded was no problem for Advance Zip Repair. However, seeing the report it became clear to me that the file didn’t contain the images I needed anyhow. 🙄

Click thumbnail to see the repair report: Advanced Zip Repair Report

Nevertheless, since only the last file was not completely recoverable I became curious and gave WinZip 10.0 and 7zip a try, too. Both programs are “regular” un-zip applications and not meant to be used for repairing ZIP files. Indeed, both were unable to open the archive (“Cannot open file: It does not appear to be a valid archive”).

Now please excuse me while I uninstall everything again…