OUTLOOK FIELD GUIDE · DOCUMENT 02
Rules & restrictions Classic Outlook for Windows · Mail views & formatting · v1.0 · Reviewed September 17, 2026
01 Functions 02 Rules 03 Hierarchy Rule index R01
A view is a presentation, not a container Documented
Start by identifying the source folder and whether results are references or actual copies.
Why it matters Deleting a result can affect an original when the result is a Search Folder reference. What to check Confirm folder type before using message actions. Related controls Sources Back to index R02
Visibility has more than one gate Guide synthesis
Folder membership, a view filter and an active search can each explain a missing message.
Why it matters Font rules cannot reveal an item outside the current result set. What to check Close Search, confirm folder, inspect Filter, then inspect formatting. Related controls Sources Back to index R03
The active window and view matter Documented
Use Explorer.CurrentView for the view displayed in the current window and retain the returned object reference.
Why it matters A correct edit to the wrong view can look like a failed edit. What to check Record folder path, view name, view type and window before changing anything. Related controls Sources Back to index R04
A screen change is not a persistence test Guide synthesis
After a view change, verify it after leaving the folder, returning and restarting Outlook.
Why it matters Saving, applying and later automation are separate concerns. What to check If it reverts, inspect the saved definition and code that reapplies a view. Related controls Sources Back to index R05
Availability is not application Documented
SaveOption describes where a view is available and who can read it. It is set when the view is created.
Why it matters An all-folders view is not proof that every folder currently uses it. What to check Check the current view in each intended destination. Related controls Sources Back to index R06
Formatting has a dedicated save Documented
Microsoft documents AutoFormatRules.Save for persisting changes to rules or their collection. Save and Apply the view as appropriate too.
Why it matters A macro can appear successful before its formatting changes are retained. What to check After code changes rules: rules.Save, view.Save, view.Apply; then perform the persistence test. Some Microsoft examples show only View.Save. This guide follows the explicit AutoFormatRules.Save method contract and does not infer a universal bug from earlier experiments.
Related controls Sources Back to index R07
Reset is not a harmless refresh Documented
Built-in views can be reset and cannot be deleted; custom views can be deleted.
Why it matters Reset can remove the customization you are trying to preserve. What to check Copy the working view and record the exact target before resetting. Related controls Sources Back to index R08
Different filters use different languages Documented
TableView.Filter and AutoFormatRule.Filter use DASL. Search-box expressions are a different interface.
Why it matters A working from: or category: search is not a ready-made VBA view filter. What to check Identify the receiving API before composing a condition. Related controls Sources Back to index R09
Width can change the layout Documented
Width-based multiline mode requires automatic column sizing; MultiLineWidth applies only in that mode.
Why it matters The same view can look different after resizing the window or Reading Pane. What to check Compare view mode, pane width and automatic sizing before rebuilding columns. Related controls Sources Back to index R10
Sort, group and automatic grouping are separate Documented
Sort fields order rows; group fields form headings; automatic grouping delegates grouping to the arrangement.
Why it matters A grouping change may resemble a sorting failure. What to check Record all three settings together. Related controls Sources Back to index R11
Grouping is not the conversation switch Documented
Conversation display options require conversation view. Setting ShowConversationByDate does not turn it on.
Why it matters A Conversation group can resemble a thread without behaving like the native conversation UI. What to check Confirm View > Show as Conversations before testing conversation options. Related controls Sources Back to index R12
Other-folder items can appear in a conversation Documented
ShowFullConversations can show related items stored in other folders when its conversation/date requirements hold.
Why it matters Visible items are not necessarily contained in your results folder. What to check Turn the option off when auditing local copies; check each item’s parent folder. Related controls Sources Back to index R13
Conversation order has a mode-specific exception Documented
ShowConversationByDate=True uses flat newest-first order; False uses indented threads with earlier roots first.
Why it matters Do not promise that the ordinary Sent sort controls every item inside a thread. What to check Check Classic Indented View and expand a sample conversation. Microsoft Support’s general newest-first statement is simplified; the VBA property documentation specifies both modes.
Related controls Sources Back to index R14
Conversation summaries are not message rows Documented limit / unverified customization
Microsoft documents bold subjects for conversations containing unread messages. A row rule is not a documented aggregate header-color rule.
Why it matters A red unread child does not establish a red header whenever any child is unread. What to check Inspect collapsed header and expanded child separately. Related controls Sources Back to index R15
Formatting has a target surface Guide synthesis
Row Font, Column Font, preview font, conditional row formatting, conversation summary and email body are distinct surfaces.
Why it matters Changing the wrong font can have no effect on the text you meant to change. What to check Point to the exact text: column heading, message row, preview, conversation header or message body. Related controls Sources Back to index R16
Built-in rules have fixed boundaries Documented
Built-in rules may be disabled but not deleted or reordered. Their Name and Filter cannot be assigned. Custom rules cannot go above or between built-ins.
Why it matters Moving a custom rule to the top is not a universal remedy. What to check Inspect Standard and Enabled; isolate the relevant built-in rule in a copied test view. Related controls Sources Back to index R17
Order is documented; universal font merging is not Documented + test required
Rules are checked in collection order. The reviewed Microsoft reference does not fully specify every overlapping-font outcome.
Why it matters Neither “last wins” nor “first wins for everything” is established here as a universal law. What to check Test one rule alone, then the overlapping pair on read and unread items; prefer nonoverlapping conditions. Related controls Sources Back to index R18
A condition reads a field, not its label Guide synthesis
A rule called PF - Direct Match does not test that phrase until its condition says so. Categories and Billing Information are different fields.
Why it matters A category can be present while the marker field is blank. What to check Inspect the exact field used by the condition on the exact displayed message copy. Related controls Sources Back to index R19
Read state can change matching Guide synthesis
The standard Unread messages rule makes unread items bold; custom rules can also depend on read state.
Why it matters A color disappearing after opening an item is evidence to inspect state-dependent rules, not proof of one particular cause. What to check Compare the same item read and unread with a single custom rule enabled. Related controls Sources Back to index R20
Reading can change data Guide synthesis
Marking a message read changes its UnRead property; view formatting may then react.
Why it matters A preview interaction may change the condition you are testing. What to check Record the Reading Pane’s mark-as-read options and compare read states deliberately. Related controls Sources Back to index R21
Separate display edits from message edits Guide synthesis
Changing a view font affects presentation; changing Categories, BillingInformation or UnRead changes an item.
Why it matters A view reset does not undo message-field edits. What to check For a copy-based workflow, write only to the intended copies and preserve existing values. Related controls Sources Back to index R22
A workflow marker is a convention Documented + workflow
Billing Information is documented as writable free-form text. Using it as a direct-match marker is a local workflow choice.
Why it matters A later macro must keep that convention consistent; the API alone does not create the marker. What to check Verify the marker after copying, moving and saving a result item. Related controls Sources Back to index R23
Item values and folder definitions differ Documented
UserProperties belongs to an item; UserDefinedProperties describes custom properties for a folder.
Why it matters A field may not be available to a view just because one item has a value. What to check Check both the item value and the folder field definition with the intended property type. Related controls Sources Back to index R24
There may be another writer Guide synthesis
LockUserChanges=True lets the UI change but prevents those UI changes from being saved. View-switch code can also react to a view change.
Why it matters Repeated reversion needs an inspection of the specific view and automation, not more random toggles. What to check Check lock state, event handlers and macro code before escalating. Related controls Sources Back to index R25
Unsupported is not the same as impossible Evidence policy
No dedicated API found means the reviewed public object model does not establish that capability. It does not prove every add-in or internal XML route is impossible.
Why it matters An experimental workaround must not become a guaranteed instruction. What to check Label evidence and test scope; use a copied view before any unsupported experiment. Related controls Sources Back to index R26
Single-line mode can be forced Documented
AutomaticColumnSizing=False or AllowInCellEditing=True forces MultiLine to olAlwaysSingleLine. ShowNewItemRow requires in-cell editing.
Why it matters Changing an editing or sizing option can change layout unexpectedly. What to check Check both settings before trying to restore multiline display. Related controls Sources Back to index R27
Collection order is not always column order Documented
ViewFields collection order can differ from the visible column order; Microsoft documents inspecting View.XML for display order.
Why it matters A diagnostic macro must not report the enumeration as an exact left-to-right layout. What to check Use the UI to verify order; read XML only if an exact automated inventory is required. Related controls Sources Back to index R28
Rule names are not unique identifiers Documented
AutoFormatRules allows duplicate names and at most 25 custom rules; built-ins do not count toward that limit.
Why it matters Repeatedly adding the same rule can create confusing duplicates. What to check Count and inspect existing matching names before creating another rule. Related controls Sources Back to index R29
Language can restrict view availability Documented
A nonempty valid TableView.Language tag restricts View-menu availability to that language; empty means all language types.
Why it matters A saved view may seem absent in a different UI language. What to check Inspect Language along with SaveOption. Related controls Sources Back to index R30
GetTable is not the rendered screen Documented
TableView.GetTable requires an active visible Explorer context; it observes the view filter but returns default table columns.
Why it matters It can audit data membership, not prove the color or order of all rendered UI elements. What to check Validate the active folder and select needed table columns explicitly. Related controls Sources Back to index Microsoft documentation establishes APIs and stated behavior. Guide synthesis is a diagnostic recommendation. Workflow notes describe a convention, not an Outlook guarantee. This reference was not live-tested against the user’s Outlook installation.
Portable ChatGPT reference