The real cost of spam

Spam costs a lot: to us regular users. A nice article about the cost we have to pay in order to defend against spam. The cost vectors (according to the article): – antispam technology Most companies deploy additional servers to filter spam. Some also buy commercial software to perform spam filtering. It needs staff to manage it, and all of these costs money. – lost productivity Spam wastes your time. It needs some attention to handle it. Note that “deleting messages, however, turns out to be the most expensive spam strategy. The average employee at companies that delete spam messages loses an average of 7.3 minutes per week looking for lost legitimate messages.” – wasted storage A usual method is to move spam emails to a quarantine. It consumes disk space, so you need additional storage capacity, and enterprise grade storage still costs. – intangible costs “Spam has a broader economic impact as well, hitting many businesses and nations that are least able to bear the burden. Consider Nigeria, for example. Nucleus Research noted that while fraud and corruption have been rampant in Nigeria for some time, the country may be forever kept in the digital darkness because of the…

Continue Reading The real cost of spam

Deploying CoreOS OVA on VMware

Deploy the vmware ova Download the OVA image from Core OS website, and deploy it to VMware using vsphere client, etc. When you boot the VM, you won’t be able to login, unless you provide coreos.autologin=tty1 as a kernel parameter to grub. If you do so, then you’ll be auto logged in as user core. Type sudo bash to get the root prompt necessary for the initial setup. Read more at http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2109161 Configure networking Create /etc/systemd/network/static.network, add the following, and finally reboot: [Network] Address=192.168.1.2 Gateway=192.168.1.1 DNS=192.168.1.100 192.168.1.101 Read more at https://www.brianchristner.io/how-to-install-and-configure-coreos-inside-vmware/ Setup ssh acccess Edit /usr/share/oem/cloud-config.yml, and add your ssh public key, eg. ssh_authorized_keys: - ssh-dss AAAAB3NzaC1kc3MAAAEBAOm5s8yJIl1ZnaqQU93f..... Then validate the settings: coreos-cloudinit --validate --from-file /usr/share/oem/cloud-config.yml If everything goes right, then apply settings: coreos-cloudinit --from-file /usr/share/oem/cloud-config.yml Now you may ssh to the host using your private ssh key as user core, eg. ssh -i /path/to/ssh.key -l core 192.168.1.2 You may want to setup etcd (version 2) etcd2: # generate a new token for each unique cluster from https://discovery.etcd.io/new?size=3 # specify the initial size of your cluster with ?size=X discovery: https://discovery.etcd.io/THE_VALUE_OF_THE_GENERATED_TOKEN # multi-region and multi-cloud deployments need to use $public_ipv4 advertise-client-urls: http://0.0.0.0:2379 initial-advertise-peer-urls: http://0.0.0.0:2380 # listen on both the official ports and…

Continue Reading Deploying CoreOS OVA on VMware

Pár érdekesség stub-okat használó email archívumból migrálás során

Chris McVeen írása Addressing Email Archive Shortcuts/Stubs when Migrating címmel, ami néhány váratlan meglepire készít fel, hogy ha migrálni akarsz egy olyan email archívumból, ami stub-okat (=pointerek a levélből kivágott és máshol található mellékletekre) használ. A migráció során ezeket a stub-okat helyre kell állítani. Az egyik ilyen gotcha a művelet során az, hogy pl. a Microsoft Exchange egy új Message-ID-t fog generálni, ha letörlöd a stub-ot tartalmazó levelet, majd lecseréled a helyreállított levéllel. Az új Message-ID pedig gondot okozhat a levelezőklienseknél. Ennél jobb a stub rehidratálás, amelynek során nem törlöd az archivált levelet, hanem a stubbing során eltávolított adatokat helyreállítod. Ebben az esetben megmarad az eredeti Message-ID.

Continue Reading Pár érdekesség stub-okat használó email archívumból migrálás során