Office Cafe

Courier-IMAP Trouble Connecting Multiple Computers

Having your own mail server can be a great experience. If you are hosting your own mail server with Courier-IMAP, you might have trouble connecting with more than one computer at the same time. I had that trouble and found the solution in the configuration file.

With my Mail application running on my desktop machine, my laptop would not connect to the server. It looked like there were SSL problems on my laptop, but it turned out not to be so. Later, I noticed that if my laptop was already connected to the mail server, my desktop machine could not connect. The message from Mail was a little misleading. It appeared that there was a problem connecting to the server because of a problem with the SSL certificate or some other SSL issue.

After a little digging around in the Courier-IMAP configuration file, I found a line that limited the maximum number of connections from the same IP address.

In a FreeBSD server, that configuration file is:

/usr/local/etc/courier-imap/imapd

I solved the problem by changing the configuration file for Courier-IMAP. Since my desktop and my laptop share the same IP, I had to tell the IMAPD configuration file that I wanted more connections from the same IP address.

The default setting was:

MAXPERIP=4

I changed it to:

MAXPERIP=8

I am not sure how many connections each computer made, but when I went from one computer to two, the default setting of 4 didn’t work. So, I doubled it, restarted the mail server and connected from two computers simultaneously.

My problem disappeared. So if you are having trouble connecting with more than one computer, try changing the MAXPERIP number to something higher. And realize that if you are connecting from a network that shares a single IP address, multiple computers will need multiple connections from the same IP address, and this needs to be managed in the imapd configuration file.

EDIT: I subsequently decided to change the number of connections to 16:

MAXPERIP=16

By observing the netstat (with this command: systat -netstat), the first computer logged in with 4 connections, the second with 5 connections. It all depends on the e-mail client and how many connections it opens simultaneously. I have not yet tried more than two clients, but I set it at 16 while I am the only one using this e-mail address from a single IP.

If you have multiple people checking e-mail from behind a single firewall (a single IP address), you may want to change this setting to something more like 5 * [number of users]. For example, 10 users could easily use up 50 connections.

To restart courier-imap on a FreeBSD 7 machine, use these two commands:

/usr/local/etc/rc.d/courier-imap-imapd restart
/usr/local/etc/rc.d/courier-imap-imapd-ssl restart

That’s it. No more trouble with multiple computers checking into your courier-imap mail server. These examples are from FreeBSD 7, with courier-imap installed from the ports collection.

I highly recommend this book: “Building a Server With FreeBSD 7″ by Bryan J. Hong. I have two posts related to it:

• Installing FreeBSD
• Errata: Building a Server With FreeBSD 7

Tags: Technical, Virtual Hosting

MacBook Air with USB727 from Verizon Wireless

MacBook Air and USB727

When it comes to working in the cafe (or in the hotel room, or in any public place), it’s great to have my MacBook Air and to be able to get online at any time, with or without WiFi available. I have found that with a few caveats, the USB727 works great!

Caution: Handle with Care. When online, put the laptop on the edge of the desk or table. Every time I set the laptop down in the middle of the table or desk, (where the USB727 touches the table beneath it), the card loses contact with the computer just long enough to throw me offline. Do that about 2 times and you’re questioning your sanity!

To solve the Handle With Care issue, use a USB extender cable (mine is unnecessarily long, but it works just fine). Unexpected Benefit of using USB extender cable: antenna positioning is much easier! If you are near a window, put the USB727 in the window, and you can move the laptop to any convenient location nearby.

Note: Battery Time Reduced. Battery time is reduced by maybe an hour or so when online. To me, it’s worth it. But I wanted to mention it. You ARE transmitting, and transmitting takes power. Hence, shorter battery life (than even WiFi).

Get The Latest Drivers

You can get the latest software from Verizon Wireless: VZAccess Download Site (http://vzam.net/).

I installed Verizon’s VZAccess Manager software to get the drivers for the USB727 on my MacBook, then promptly stopped using it. Instead, I use Mac OS X’s network connection software (built into Mac OS X) to connect.

Connect With System Preferences

Connect by selecting System Preferences > Network (leave everything blank), click on the Connect button. See this post for complete instructions:

• How to Connect USB727 Using System Preferences

Summary

Verizon’s coverage is great in my travels, and it’s a nice backup to my iPhone! Yes… I use AT&T and Verizon. It’s really a great combo for places where one company has better coverage than the other (it happens, current advertising campaigns notwithstanding)!

I hope this helps anybody considering the MacBook Air / USB727 combination. I’m glad to have both in my laptop briefcase!

For more photos, see:

• MacBook Air and USB727 Photos
• MacBook Air and USB Swivel Adapter for USB727

Tags: Mac

Switching Mom and Dad to Mac

This was a banner week! Mom and Dad decided to replace their WindowsXP machine with an iMac. Yes, they are grandparents and yes, they decided that they could learn a new operating system. Their needs are normal: e-mail, web browsing, and looking at pictures of their (nearly grown) grandchildren.

The setup was easy (except for Bellsouth’s e-mail). The e-mail setup would have been a little easier if we had the correct passwords. (The ones they had written down were not correct). After a little help from AT&T (which now owns the Bellsouth assets), we were able to get them to check their e-mail.

Sending e-mail, however is a bit of a trick with AT&T/Bellsouth accounts. After scouring the web for a few minutes and working out when to put the full e-mail address instead of just the username portion (the part before the @ symbol), we finally got mail outgoing. Once you know where to put what, Mac OS X’s Mail 3 Application works just great, even with AT&T/Bellsouth.

I got e-mails from both Mom and Dad, so I know everything is working. My mom thinks she may have deleted a bunch of her mail, but I assured her that they were simply in the trash, and could be gotten back if she moved them back to her inbox before the week was out (Mail defaults to emptying messages from the trash after a week).

The best part of switching them to Mac, was … drumroll please … I can now help them over iChat! I can request to take over their screen, move the mouse and help them do whatever they wanted to accomplish, all the while maintaining an audio chat while I help them.

Well, actually, that’s not the best part of switching them to Mac. The best part is that I don’t have to worry about them getting viruses, keyloggers, shopping “helpers”, spyware, and other malware that is often found on Windows machines. I know, they are not non-existent, but my experience (and those of my teenagers on their own MacBooks) has been that viruses are MUCH harder to get.

The part they seem to like best is video chatting. It is so easy with iChat. With our oldest going to college away from home next year, they are looking forward to “seeing” her, even when she is in school.

I rest easier knowing that helping them accomplish anything on the Mac is only a mouse-click away. Not that I mind helping them in person, it’s just that sometimes a small matter can be cleared up in just a few minutes over iChat. And we can get caught up with the latest happenings, all at the same time!

Congratulations Mom and Dad!

Tags: Mac, Think

Back to the Original Server

A few days back, I decided to move OfficeCafe to another server so I could rebuild this one. It’s done. I had about a half hour of down time while I made the old server stop listening for connections, powered up the new server, and made WordPress talk to MySQL again.

Again, Bryan J. Hong’s book, Building A Server With FreeBSD 7, came in real handy. I had rebuilt this server so that my standard directory structures could be implemented.

The main problem I had was that WordPress could not access the MySQL database. Checking back in the book, I realized that I had missed a step on page 215. I needed to create the wordpress.conf file and restart Apache. MySQL also needed to be restarted:

# /usr/local/etc/rc.d/mysql-server restart

That did the trick. We’re back and running. The preparation for the move back involved backing up the database(s), copying them to the new server, and restoring them.

There are a lot of details involved in moving a WordPress blog from one server to another (and back)! I don’t recommend making a habit of it. But in the process, I realized that having a backup of the database and the root directory of the blog is a great thing to do. If I need to move it to another server, I should be able to pick up the main files and drop them into place and keep going!

Tags: Technical, Virtual Hosting

The Third Place

Over at Coffee Shop Journal, Marla talks about one of my favorite topics. I love to be in the Coffee Shop, just bumping into the people. If you frequent one or two shops with any regularity, you will get to know the people around you. Sometimes you don’t get a chance to know their names, but even so, you nod or smile to acknowledge that they exist. Even that can be a comfort to some lonely soul.

Her blog post is a fun read. She names a few regular characters and a few that just pass through. Take a minute and read it.

And oh, The Third Place? Well there is already a lot on the topic, but if home is the First Place, work is the Second Place, the Third Place is where you hang out: church, the coffee shop, the mall, the park, the bookstore, etc. See Marla’s blog. She describes it in several posts.

Tags: Think, Third Place