Skip to content 
Is your strato email storage fullThis blocks new messages and can even lead to loss. I'll show you clear steps on how to free up space for emails immediately. legally compliant and keep your mailbox permanently lean.
Key points
- Sort by size and age is the fastest way to save memory.
- Wastebasket empty, otherwise the space will remain occupied.
- Archive keeps mails available locally or in the cloud.
- Filter and rules prevent it from filling up again.
- Upgrade or change only in the event of a permanent bottleneck.
Why the Strato storage fills up
IMAP mirrors all mails and attachments on the server, which means that mailboxes grow steadily over the years and take up space. Gigabyte. Large PDF files, image galleries or presentations drive up the limit. I often find that folders such as "Sent" and "Archive" take up the most space unnoticed. Infrequent deletion increases the effect because mails with attachments are often in the inbox and the Sent folder. A mailbox then reaches the tariff limit, new emails bounce off and important News no longer arrive.
Quick check: find memory hogs
I always start with a size check in the Strato webmailer or in the mail program. Sort mails by Size and old order, so you can find the big chunks in seconds. First look in Inbox, Sent and Archive, then in folders with project files. Also check whether there are subfolders with lots of images or ZIPs. If you want to use the webmailer more efficiently, this compact guide will help you Strato Webmail Guide with important functions and safety tips to help you tidy up faster and keep your Workflow improve.
Targeted deletion - with effect
I delete the largest emails first, because 20 distant giants often take up more space than 500 small ones Notifications. Open the sorting by size, mark the top emails and remove them in blocks. In particular, reduce attachments that you have already saved in project storage. Then remove old serial emails such as newsletters and status updates that are of no evidentiary value. Finally, check the folder structure and delete duplicate Folder or outdated topic data.
Empty trash and sent items - the double lever
Many people overlook the fact that the recycle bin continues to block the memory. After each deletion run, I empty the Wastebasketso that the free space is immediately visible. The "Sent" folder often contains all attachments a second time, which doubles the load. Remove older conversations with large files from there or move them directly to the archive. This allows you to quickly gain reserves and keep the Inbox clear.
Archive instead of storing in the mailbox
I archive all emails with proof value locally or in a verified cloud so that the mailbox remains free. Outlook, Thunderbird and Apple Mail offer archive or local storage for this. Folderwhich you fill using drag-and-drop. The effect is immediately noticeable because the moved mails disappear on the Strato server. For additional security, I keep at least one backup on an external data carrier. If you want to work in the long term, use a clear Archive concept with fixed rules.
Outlook and Apple Mail: brief instructions for the archive
In Outlook, I select the time period (e.g. older than 12 months), click on "Archive" and save as a PST on my computer. I then delete the archived emails on the server so that the Memory becomes free. In Apple Mail, I right-click to move folders to "On my Mac" and keep copies locally. Check regularly whether your backup is running, because an archive needs reliable backups. This keeps the Strato mailbox lean and your Proof remains available.
Automatic rules and filters against mail floods
I create rules that move newsletters, status mails or automatic replies to a shared folder. This keeps the inbox for Important free and I decide together what can be deleted. For project agreements, I use keywords or categories to define deletion cycles. Rules also help when removing old versions of files that have been sent by email. I use a calendar entry to check the largest files on a monthly basis. Folder and move old items directly to the archive.
Upgrade or switch: when it makes sense
If the memory remains permanently tight despite the archive, I calculate an upgrade or check alternatives. I compare the setup, storage, expandability and security functions before making a decision. In the case of heavy email usage, more powerful hosting with flexible upgrades and more Control be useful. You can find details on typical mailbox sizes and tariff issues in these compact Strato details on e-mail hosting. The following overview shows a simple classification from practice, as I use it to make decisions. use:
| Provider | Storage space | Flexibility | Security | Recommendation |
|---|---|---|---|---|
| webhoster.de | Very high | Very flexible | Very good | 1st place |
| Strato | Medium | Medium | Good | 2nd place |
| Other | Different | Different | Different | Subordinated |
Legal matters at a glance: Storage and GDPR
I store business emails in an audit-proof manner in accordance with legal deadlines (e.g. 6 or 10 years). To do this, I use an archive with clear Rulesregular backups and access control. If you want additional security, check out specialized archiving software and cloud solutions based in the EU. This guide provides a practical introduction to legally compliant filing. Strato e-mail archiving. How to fulfill obligations and keep your productive mailbox permanently slim.
Send large attachments differently
I send large files via shared storage locations or project folders instead of as email attachments. This reduces mailbox growth for me and my contacts. At the end of the project, I remove outdated file packages from the mail archive and only keep the final files. Versions. I define clear rules for recurring processes: Send link, store file centrally, save mail without attachment. This keeps communication easy and the Memory grows much more slowly.
My maintenance plan for a permanently lean mailbox
I plan a 15-minute routine every week: check large emails, empty the trash, refine rules. Once a month, I archive older folders and back up a Backup. Every quarter, I check the largest folders and delete outdated threads including duplicates. I save attachments centrally in project rooms and remove them from the Sent folder. This little discipline keeps the mailbox agile and I stick to mailing capable of acting.
Quick-win checklist without bullet points
Start by sorting by size and remove the top 50 mails with attachments. Empty the recycle bin immediately and check "Sent" for duplicate loads. Then move old annual folders to a local archive and check the Backup. Build at least two rules: Collect newsletters, auto-reports into a control folder. Make a note of a monthly deadline to monitor growth and free time. Capacity to be checked.
Strato-specific: Memory display, quota and notifications
I like to start directly in Strato Webmailer by looking at the storage display. There I can see what percentage is occupied and which folders contribute the most. It's practical that I can sort by size with one click and also check the allocation in the context menu of folders. If you frequently reach the limit, set up notifications: Many mail clients support rules that trigger an alarm in the event of delivery errors (e.g. quota exceeded). I also make a note of a fixed limit, such as 80 % or more, above which I actively thin out. This prevents escalations before important News bounce off.
Detach attachments instead of deleting mail
The space is often taken up by the attachments. I save these separately and then remove them from the mail, while the correspondence remains intact. In Outlook, I use "Save all attachments" to save the files in the project folder and then select "Remove all attachments". In Thunderbird, I use "Save attachments" and then "Remove attachments". In Apple Mail it works with "Email" → "Remove attachments". Important: These actions change the mail on the server. I only do this if the files are safely stored in my project storage and a Backup exists. The effect is enormous: a handful of emails with 25 MB attachments quickly frees up hundreds of MB.
Search like a pro: size filters, attachments, duplicates
I use the combination of search and sorting in all clients. Search for terms such as "invoice", "quote", "report" in conjunction with "has attachment" and select the "by size" view. Threads with many replies often contain attachments in multiple replies - I keep the last, complete version and delete intermediate versions. If your client offers duplicate search, I run it through folders like "Sent" and "Archive". This way you remove multiple files without losing context.
Thunderbird, Outlook and Apple Mail: advanced clean-up tricks
I regularly "compact" folders in Thunderbird. This permanently removes items marked as deleted and ensures clean IMAP synchronization. In Outlook, I set AutoArchive rules at folder level for large mailboxes: everything older than 12 months is moved to a PST. If you work with OST caches, you can temporarily reduce the synchronization limit to reduce the local load - on the server side, the deletion strategy remains decisive. In Apple Mail, intelligent mailboxes, such as "Larger than 10 MB" or "Has attachment", help to move specific items. After large deletion runs, I rebuild the indexes in all clients once so that searches run at lightning speed again.
IMAP vs. POP3: When local retrieval helps
I recommend IMAP for collaboration and device separation. In exceptional situations - for example if the mailbox is acutely blocked - a temporary POP3 retrieval can help to save emails locally and delete them on the server side. I only use this deliberately, document the time period and then carefully check whether all relevant emails have ended up in the archive. For continuous operation, I stick with IMAP and move mails in a structured way to local archives. Folder or a legally compliant archive.
Structure that supports: Naming and annual folder
I create a clear folder structure so that the next clean-up process is quicker: "01_Inbox", "02_Processing", "03_Archive_Year", plus project abbreviations such as "CUSTOMER-XYZ". I keep quarterly or topic subfolders in the annual archives. I tag important emails with categories such as "Contract", "Invoice", "Proof". This allows me to recognize later what subject to retention and can move it specifically to an audit-proof archive. These naming conventions make rules simpler and prevent uncontrolled growth.
Team mailboxes and shared responsibility
I define responsibilities in shared mailboxes: Who deletes newsletters, who archives project results, who checks the largest folders every month? I keep rules consistent across the team so that nothing is saved twice. I use a clear policy for "Sent": only the final version with attachment remains, interim statuses go to the project drive. If there is a high volume of mail, I divide mailboxes according to function addresses (e.g. support@, rechnung@) - this makes it easier to check quotas and to manage them later. Archiving.
Emergency plan: If your mailbox is already blocked today
I act in five steps: Firstly, I empty the recycle bin completely. Secondly, I delete the ten largest conversations with attachments in the "Sent" folder. Thirdly, I temporarily move the largest emails in my inbox to a local folder to free up space. Fourthly, I briefly inform important contacts that emails will be delivered again. Fifthly, I immediately save a Backup of the local filing system and plan permanent archiving. This means that the mailbox is ready to receive again in minutes without losing any evidence.
Mobile devices: clean up without risk
On my smartphone, I only delete things that are clearly unnecessary (newsletters, promotions, automatic confirmations). Sorting by size is often limited on mobile devices, so I do the large deletion and archiving steps on the desktop. I deactivate the automatic full download of all attachments on mobile devices to save data volume and device memory - this doesn't save any space on the server side, but keeps the clients responsive. When traveling, I set up a "Check & Delete" smart mailbox that only shows emails with attachments.
Backup strategy: testing, not just planning
An archive is only as good as its Backup. I follow the 3-2-1 rule: three copies, two media types, one external copy. I also test the restore of a random sample every quarter: open PST or MBOX, check search function, open files - only then do I cancel the run. I encrypt sensitive emails on the backup medium. So the Storage not only formally correct, but also practically usable.
Typical mistakes that I avoid
I never "blindly" delete entire annual folders without looking at attachments. I don't rely solely on the search, but combine filters, sorting and folder browsing. After mass deletions, I always check the recycle bin and deliberately empty it. And I always keep in mind that the "Sent" folder is a silent memory hog - the same attachments are stored there a second time. With this discipline, the Memory under control.
Conclusion: How to keep your Strato mailbox free
If you are running out of memory, start by organizing large emails and the Sent folder. Archive consistently, back up your data and keep simple Routines on. With rules you stop new floods, with alternatives to attachments you permanently reduce the volume. An upgrade or change only pays off if the bottleneck remains despite discipline. How to stay in control and keep your inbox clean ready to receive and no longer lose any important messages.
