"Current notices about Posteo: News, developments, background information and media appearances."

Blog and Media


New security certificate

Created on 23. February 2024, 11:35 | Category: Info

Dear Posteo customers,

We are updating our main security certificate. Security certificates are only valid for a specified time period and need to be renewed from time to time.

In most cases, you will not notice any change.
All current clients like Thunderbird or Outlook will automatically find the new certificate. You do not need to do anything. However, should your client display a certificate error during this changeover process, please restart your client. This should fix the error.
If you manage the trustworthiness of certificates manually, you can find the fingerprint for the new main certificate below. You can also find complete fingerprints for all certificates in our legal notice.

New fingerprint for the TLS security certificate for

SHA256: AA:FC:E1:21:F4:15:14:E6:8D:09:ED:F4:87:EA:E6:1E:02:99:BC:9B:41:51:4C:FC:DC:BE:F5:E8:A5:60:9C:DD
SHA1: ED:87:9A:C6:E6:2E:72:82:42:AD:30:D9:05:38:30:34:7C:47:2F:24

Best regards,
The Posteo Team

Now available: and additional Posteo domains

Created on 15. December 2023, 13:45 | Category: Info

Dear Posteo customers,

We are expanding our range of services: From now on, accounts can also be registered with the email domain Additionally, we offer the domains,,,,,,,,, and


Previously, accounts could only be registered with either or endings. Many of you have asked for these additional options.

If you prefer one of the new domains for your existing account, you can now rename it easily in the settings via “Email aliases”. Your previous address will then be converted into an alias, so that you can continue to receive emails to that address.
If necessary, you can find further information in our help section.

There are many other top-level domains (the address part after “@posteo.”) also available for Posteo email aliases, such as .me or .eu.

By the way: Your Posteo address can only be registered by you for the other Posteo domains. For example, if you have the address, only you can register the address

Best regards,
Your Posteo Team

New at Posteo: Optional spam folder and spam log

Created on 17. October 2023, 17:20 | Category: Info

Dear Posteo customers,

We have released two new spam options. From now on, you can manage your mailbox with or without a spam folder – or use the spam log. The new options can be activated or deactivated in your account settings. Allow us to introduce them to you.


If you do not use a spam folder, emails that have been classified as spam are rejected and the sender is informed of this rejection. You save time in your daily routine as there is no spam folder that must be checked regularly and sorted through. Because from a legal point of view, emails in a spam folder are also generally considered as delivered. Additionally, your email address becomes considerably less enticing for spammers if their potentially dangerous digital trash is regularly rejected.

Attempts to reach out to someone are also often overlooked in spam folders or noticed much later. This is the reason why the Snoop Dogg song “Chai Tea with Heidi” almost didn’t exist because Heidi Klum overlooked an email sent by the rights holder, Rod Stewart, for almost two months in her spam folder. Email clients like Thunderbird, Outlook or smartphone apps may even automatically delete emails in spam folders after a short period of time. Therefore, please be sure to check the settings for deleting emails in your programs if you use a spam folder. Otherwise, communication could be lost. We do not delete emails from the spam folder.

Spam illustration

Spam folder: Receive all spam emails

Whoever decides to use the optional spam folder can check there at any time which emails have been classified as spam by us. All spam emails will be delivered in this folder.

From a customer service perspective, we know that it is very uncommon for spam to be falsely classified and is mostly only suspected. If an expected email is missing, in most cases it turns out that either the email address was misspelled or the message was sent to another email address. Often the email in question arrives shortly thereafter. Sometimes customers have also activated a filter that immediately sorts incoming emails to subfolders or deletes them. Or they use external email clients that sort emails into their own spam folders. Sometimes, it’s just that the inbox has also been accidentally sorted differently – and incoming emails are not longer displayed as usual.

Please check the scenarios described above if you have activated the spam folder and suspect that an email has not been received. From a technical standpoint, you can be sure that we deliver all emails sent to your mailbox, even if they have been classified as spam.

Activating the spam folder can lead to your email address becoming considerably more attractive for spammers – and result in you receiving more spam. Therefore, you can also temporarily activate your spam folder as needed. For example, during a period where you are sending off job applications and want to be absolutely sure that nothing can go wrong under any circumstance or that something may need to be clarified first.

Screenshots of the spam log in the Posteo web app
The spam log in the Posteo web app

Steer a middle course with the spam log

Are you not interested in managing a spam folder but still want to know which emails are rejected? Then, as an alternative to the spam folder, you can activate our new spam log.

By doing so, potentially dangerous spam emails will continue to be rejected. We also document each rejection for you transparently in a spam log folder. The log contains details about the sender, date, time and subject (if applicable) of the rejected email and is created in real-time. Warning: Sender names are often falsified by spammers.

Should you suspect that an email has been incorrectly rejected, you can check the log and know with immediate certainty.

Screenshot of a spam message
Images, attachments and links are deactivated in the spam folder

Be careful with spam

Regardless of whether you decide for or against a spam folder: Always be careful when dealing with suspicious emails. Never click on links or open attachments in such emails and never answer them. In general, legitimate senders do not request that you click on links and then enter login credentials or other data. For your security, images are not loaded in the spam folder and clicking on attachments and links is deactivated in the Posteo interface and our web app. If you move the email to another folder, contents can be loaded and clicked on as usual.

If a sense of urgency is suggested or pressure is exerted, it is often a clear indication of spam or phishing. This rule of thumb helps: Never give in to such harassment. If you are unsure, you can always first contact our free customer support. We can advise you how to deal with suspicious emails. There are also no dumb questions: Even IT professionals can become unnerved by well-made spam emails and will contact us. Our team always takes you seriously.

Best regards,
Your Posteo Team

Posteo awarded climate mobility prize from Deutsche Bahn

Created on 05. July 2023, 10:00 | Category: Blog

The award presentation at Deutsche Bahn

Posteo is the winner of Deutsche Bahn’s “Climate Mobility Challenge 2023”: At the award presentation in Berlin on 29 June, we were recognised for our sustainable mobility program.
Since 2022, Deutsche Bahn has aimed to incentivise companies with their competition to reduce CO2 emissions through environmentally-friendly mobility practices.


After the jury nominated us for the award in the “small company (up to 50 employees)” category, the final decision was made by the audience on Thursday evening during Deutsche Bahn’s “Mobility Symposium”. Afterwards, Posteo founder, Patrik Löhr and Dean Ceulic, accepted the award from Deutsche Bahn executive board member, Stefanie Berk.
We are pleased about the award!

An overview of our award-winning mobility program

Our team consists of 40 employees spread out all over Germany. Our mobility program is a part of the entire company’s sustainability strategy – over the years we have continued to expand upon it.

The Awards
The Awards

No Flights Policy: For climate protection reasons, we have refrained entirely from aeroplane travel already since our founding in 2009. In our experience, we have found that many destinations in continental Europe are also very accessible by train with regard to business trips.

Facilitating environmentally-friendly trips: Since 2014, we grant our employees 2 additional vacation days per year if they refrain from using aeroplanes when travelling abroad privately – and we also contribute towards travel costs (150 €, net) for the train ticket. Our intention with this voluntary offer is to create an incentive for environmentally-friendly trips by train and to compensate with additional vacation days for the longer journey. Since many years, this offer has been adopted and valued by our team.

Remote Positions: Most team members can work fully remotely as their positions allow for this. This reduces commuting and CO2 mobility-related emissions. We have decided to continue to offer remote work on an ongoing basis, even after the pandemic.

Free public transportation ticket: We provide all employees with a public transportation ticket free of charge. In fact, this also applies for those who work exclusively remotely or do not live in Berlin, where our company is located.

Accessible location: our offices are located centrally in Berlin and are easy to reach using public transportation, by bike or by foot.

Bike repair: we cover maintenance and repair costs, including replacement parts, for bikes that are also used for travelling to work. Our team gladly takes advantage of this offer. Additionally, we have rented car parking spots in the underground garage located beneath our office to set up secure bike parking.

Idea pool for companies

The prize winners in 2023
The prize winners in 2023

The “Climate Mobility Challenge” (German link) is a competition from Deutsche Bahn for companies and organisations to make sustainable employee and event mobility visible:
Company mobility policies are presented from a wide range of industries and company sizes on the competition website. As a result, it also serves as an idea pool for companies that are searching for sustainable mobility solutions.

In total, 54 companies participated in the competition this year. There were three categories: small, medium and large companies. Additionally, there was a special award in the “event mobility” category. In total, there have already been 120 mobility policies presented on Deutsche Bahn’s idea platform

“Employers are multipliers, bear responsiblity and can do a lot to avoid emissions through company policies. At Posteo, we also try to incentivise more climate protection in everyday life with free additional benefits for our team. Participating in the competition motivated us to expand upon this”, said Posteo founder, Patrik Löhr, during the award presentation.

Girls'Day 2023 at Posteo

Created on 11. May 2023, 17:30 | Category: Blog

Making coding exciting for girls: This is what our team set out to do for this year’s Girls’Day.
It was a special experience for us to welcome female students interested in computer science at the Posteo Lab located on top of Berlin’s Kreuzberg – and to give them insight into the job of a software developer.


The Posteo Girls'Day Team
Email workshop at Girls’Day 2023

Starting steps for computer science

After a round of getting to know each other, our developer Monika shared how she trained for her profession. She told the girls what subject matter should be expected when studying computer science and what job possibilities exist afterwards. She then answered questions regarding choosing a profession and everyday life on the job.

Workshop: How email protocols works

Afterwards, there was a more detailed look into working as a developer. Our team explained to the students what protocols are, what role they have in the global exchange of information – and how the SMTP protocol (Simple Mail Transfer Protocol) is used for transferring emails.

Finally, it was the girls’ turn: With help from Anne, a team leader from our technical support, they could communicate with an email server using SMTP protocol, enter commands and deliver emails from the command line.

The Posteo Lab with a Posteo flyer in the foreground
Girls’Day 2023 at the Posteo Lab

Choosing a field of study or profession without gender stereotypes

Our Girls’Day Team enjoyed the day very much. “We want to give girls the chance to meet women who work in software development and by doing so contribute to changing old role models. The profession is multifaceted, attractive and it should be normal for girls to pursue it if they are interested,” says Posteo developer, Monika. “It was so nice to see how motivated the girls were to participate. We will definitely take part again next year.”

Girls’Day is a day of action for career guidance in Germany. On this day, girls in the 5th grade and higher can gain more insight into jobs that are primarily chosen by men.
This includes software development. Posteo’s development team has a balanced ratio between men and women. Many of our features were programmed by women: for example the Posteo migration service, our mobile user interface, the attachment browser with photo stream – and also our new dark mode. But it’s not like that everywhere: In computer science studies and in the technology sector, women in Germany are still strongly under-represented.