Hi All!
Most of us on the list have been wrestling with
deciding whether to stick with Imail, upgrade to ICS
(HA!), or bail to Smartermail, Kerio, Merak, or
Linux/open source solutions.
We recently migrated from Imail to Merak 7.6/8.0
(version 8 was released during roll-out), and I thought
I would share my experiences in the context of a
replacement for Imail. Hopefully others will do the
same with Kerio, SmarterMail, etc., for the benefit of
those here. Every situation is different and there is
no single correct answer for everybody. Who knows, it
may well become apparent that Imail 8.2 is worth
sticking around for!
Remember, the following are my observations and
opinions--your mileage may vary. :-)
Overall, I am very pleased with Merak, and while it has
documentation rough spots, the stability, speed, and
maturity of this product are in a completely different
league than Imail 7,8, and 8.1. (The changes coming in
IMail 8.2 are welcome but way overdue--I completely
lost confidence in Ipswitch product development 18
months ago.)
Here are my Pros and Cons:
***PRO***
1. Average CPU Usage has gone from Imail's 30-75% to
just 0-2%. This reduction amazed me. (It does spike to
100% for 3-4 seconds if opening webmail with 2000+
messages present in main inbox.)
2. Merak's tarpitting is a godsend in dealing with
dictionary attacks (and the main reason for our
previously high cpu usage with Imail). We have 20-100
IP's tarpitted at any given moment. We sometimes had
50K-200K attack connections/day. Because we do business
all over Asia and Europe, using country IP netblocks to
combat attacks is out of the question. With Merak, it's
simply not a problem anymore.
3. Built-in antivirus engine (avast I believe) is fast,
configurable, and solid. Probably not as flexible as
Scott's Declude (which I've not used), but pretty good.
It's catching everything SMSSMTP used to catch, plus
more. Best feature: this scanning engine is FAST FAST
FAST. Good logging, too.
4. DNSRBL can be used as a stand-alone block list, or
you can have multiple RBL hits included as weighting
factors in total scoring (like Declude) in integrated
spam assassin.
5. No more IMail file-locking issues (mbox) during
POP3/SMTP access of large mailboxes. Merak uses an
individual text file for each message (maildir). (See
CON section for downside.)
6. Webmail is world class, fully-featured, and very
robust. Has it's own rock-solid PHP engine--IIS not
required. Lots of skins to choose from--from a
feature-rich multi-paned "Outlook 2003" style to
Squirrel Mail-like single-pane type. We've found the
fast, bandwidth-efficient single-pane interface is a
blessing for mobile users--seemingly always on the
other side of globe accessing from third-world
countries with horrid connectivity.
7. The total feature list is staggering, and everything
appears solidly implemented, including SPF, SURBL,
Bayesian Filters, listserve, auto-archive, SSL ports
for all protocols, etc,. And in contrast to Imail,
practically every setting has a separate bypass file,
making it very flexible.
8. It has a nice GUI implementation of what are truly
awesome content filters. The name "content filters"
doesn't do them justice. The power and flexibility of
these filters and associated system variables will take
any admins' breath away--you can accomplish practically
ANYTHING with these. To me, this is probably Merak's
greatest, but most unsung feature.
8. Log entry timestamps include GMT offset, a small
point but appreciated when you deal with a variety of
app and server logs generated on three continents.
9. IMAP is rock solid, and (so far) plays nice with all
clients. (In all fairness, Imail's was very good, too.)
The unique shared IMAP folders have also come in VERY
handy! (An ISP won't, but most who support company
users will realize the value.)
10. Groupware/global address book works well (once you
get past the mediocre docs). I don't know how they
compare to ICS. The Imail KWM GAB is a joke.
11. User management interface in all respects is at
least equal--and in most cases far exceeds--that of
Imail in ease and power. BTW, ALL Merak management,
configuration, and reporting tasks can also be done via
a single command line tool (appropriately called
tool.exe).
***CON***
1. Setup and tuning can be a challenge--or a piece a
cake--depending on your config complexity.
Configuration is done in several different places.
(MUCH better organized in version 8 though.) Part of
problem is that Icewarp WebMail is also offered as a
standalone product, so sorting out advanced settings in
the docs can be confusing when in "fully integrated"
mode.
2. The docs/help file rating is mediocre-to-sucks. Fine
as far as they go, but not enough depth and awkwardly
translated in places. Some good examples in config
files, but not enough. Version 8 is better, but still
needs improvement. TIP: Viewing the html tutorial
offered during Merak setup should NOT be skipped. Lots
of valuable info not in the docs are here, and much
better english. :-)
2. Webmail reporting is skimpy compared to Imail.
SMTP/IMAP/POP3 logs are comparable to Imail, but SMTP
log seems to omit writing a final local mailbox
delivery success entry.
3. Webmail response opening huge mailboxes (1.5GB -
17000 messages) is glacial. Anything over 1200 messages
requires a noticeable wait. Surprisingly, Imail
webmail--while comically pathetic in most areas--WAS
pretty good opening gargantuan mailboxes.
4. Because Merak uses maildir instead of mbox as the
message storage format, keeping your disks defragged is
even more critical to performance--especially webmail.
I STRONGLY suggest using a defragger that monitors
realtime, and automatically kicks in when frag reaches
a certain level (like O&O).
I sometimes find myself grinning at Merak's processing
speed. In my opinion, Merak has the flexibility and
throughput of the best of the UNIX-based mail servers.
Once the initial configuration was ironed out (ours is
necessarily complex), the little PE600SC P4/2.4Ghz box
loafs like a qmail box. Users are much happier now, and
when asked, not a single person wants to go back to
Imail. Very telling. No memory leaks either, (55 days
continuous service uptime and counting, over a hundred
gigs of various mail protocols though it--memory usage
has not budged in nearly two months.)
For companies, I can recommend Merak. The docs ARE
adequate for most standard configs--you just install
and go. The more customizing you do, the more you wish
the docs explained better all the myriad choices Merak
is capable of.
I've never had to administer hundreds or thousands of
ISP domains, but the command line tool seems well
suited for mass-user ISP scripting. I've not used them,
but there is configuration for setting automatic domain
expiration and notification, domain disk quota, and
individual user limits on MB and outbound messages
sent.
My biggest complaint about Imail was not the
features--it was the half-baked implementation of most
of them. It was maddening--enough functionality to be
ticked on a feature list, but often inflexible,
untweakable and sometimes pathetically unusable. In
contrast, Merak has the features, most completely
customizable and bullet-proof, but with mediocre/poor
documentation. :sigh:
In my opinion, Merak's initial doc hurdle is well worth
the truly staggering performance and stability
improvement.
Our cost for unlimited users/domains, with 100 account
groupware and instant messaging, was $1500.
Dev
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html
List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
