diff --git a/agents/unifiedmailboxagent/unifiedmailboxmanager.cpp b/agents/unifiedmailboxagent/unifiedmailboxmanager.cpp
index cb9525b3b..fd7af4a61 100644
--- a/agents/unifiedmailboxagent/unifiedmailboxmanager.cpp
+++ b/agents/unifiedmailboxagent/unifiedmailboxmanager.cpp
@@ -1,441 +1,445 @@
 /*
    Copyright (C) 2018 Daniel Vrátil <dvratil@kde.org>
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program; see the file COPYING.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 */
 
 #include "unifiedmailboxmanager.h"
 #include "unifiedmailbox.h"
 #include "unifiedmailboxagent_debug.h"
 #include "utils.h"
 #include "common.h"
 #include "settings.h"
 
 #include <KSharedConfig>
 #include <KConfigGroup>
 #include <KLocalizedString>
 
 #include <AkonadiCore/SpecialCollectionAttribute>
 #include <AkonadiCore/CollectionFetchJob>
 #include <AkonadiCore/CollectionFetchScope>
 #include <AkonadiCore/LinkJob>
 #include <AkonadiCore/UnlinkJob>
 #include <AkonadiCore/ItemFetchScope>
 #include <Akonadi/KMime/SpecialMailCollections>
 
 #include <QList>
 #include <QTimer>
 
 namespace {
 /**
  * A little RAII helper to make sure changeProcessed() and replayNext() gets
  * called on the ChangeRecorder whenever we are done with handling a change.
  */
 class ReplayNextOnExit
 {
 public:
     ReplayNextOnExit(Akonadi::ChangeRecorder &recorder)
         : mRecorder(recorder)
     {
     }
 
     ~ReplayNextOnExit()
     {
         mRecorder.changeProcessed();
         mRecorder.replayNext();
     }
 
 private:
     Akonadi::ChangeRecorder &mRecorder;
 };
 }
 
 // static
 bool UnifiedMailboxManager::isUnifiedMailbox(const Akonadi::Collection &col)
 {
 #ifdef UNIT_TESTS
     return col.parentCollection().name() == Common::AgentIdentifier;
 #else
     return col.resource() == Common::AgentIdentifier;
 #endif
 }
 
 UnifiedMailboxManager::UnifiedMailboxManager(const KSharedConfigPtr &config, QObject *parent)
     : QObject(parent)
     , mConfig(config)
 {
     mMonitor.setObjectName(QStringLiteral("UnifiedMailboxChangeRecorder"));
     mMonitor.setConfig(&mMonitorSettings);
     mMonitor.setChangeRecordingEnabled(true);
     mMonitor.setTypeMonitored(Akonadi::Monitor::Items);
     mMonitor.setTypeMonitored(Akonadi::Monitor::Collections);
     mMonitor.itemFetchScope().setCacheOnly(true);
     mMonitor.itemFetchScope().setFetchRemoteIdentification(false);
     mMonitor.itemFetchScope().setFetchModificationTime(false);
     mMonitor.collectionFetchScope().fetchAttribute<Akonadi::SpecialCollectionAttribute>();
     connect(&mMonitor, &Akonadi::Monitor::itemAdded,
             this, [this](const Akonadi::Item &item, const Akonadi::Collection &collection) {
         ReplayNextOnExit replayNext(mMonitor);
 
         qCDebug(UNIFIEDMAILBOXAGENT_LOG) << "Item" << item.id() << "added to collection" << collection.id();
         const auto box = unifiedMailboxForSource(collection.id());
         if (!box) {
             qCWarning(UNIFIEDMAILBOXAGENT_LOG) << "Failed to find unified mailbox for source collection " << collection.id();
             return;
         }
 
         if (box->collectionId() <= -1) {
             qCWarning(UNIFIEDMAILBOXAGENT_LOG) << "Missing box->collection mapping for unified mailbox" << box->id();
             return;
         }
 
         new Akonadi::LinkJob(Akonadi::Collection{box->collectionId()}, {item}, this);
     });
     connect(&mMonitor, &Akonadi::Monitor::itemsRemoved,
             this, [this](const Akonadi::Item::List &items) {
         ReplayNextOnExit replayNext(mMonitor);
 
         // Monitor did the heavy lifting for us and already figured out that
         // we only monitor the source collection of the Items and translated
         // it into REMOVE change.
 
         // This relies on Akonadi never mixing Items from different sources or
         // destination during batch-moves.
         const auto parentId = items.first().parentCollection().id();
         const auto box = unifiedMailboxForSource(parentId);
         if (!box) {
             qCWarning(UNIFIEDMAILBOXAGENT_LOG) << "Received Remove notification for Items belonging to" << parentId << "which we don't monitor";
             return;
         }
         if (box->collectionId() <= -1) {
             qCWarning(UNIFIEDMAILBOXAGENT_LOG) << "Missing box->collection mapping for unified mailbox" << box->id();
             return;
         }
 
         new Akonadi::UnlinkJob(Akonadi::Collection{box->collectionId()}, items, this);
     });
     connect(&mMonitor, &Akonadi::Monitor::itemsMoved,
             this, [this](const Akonadi::Item::List &items, const Akonadi::Collection &srcCollection,
                          const Akonadi::Collection &dstCollection) {
         ReplayNextOnExit replayNext(mMonitor);
 
         if (const auto srcBox = unifiedMailboxForSource(srcCollection.id())) {
             // Move source collection was our source, unlink the Item from a box
             new Akonadi::UnlinkJob(Akonadi::Collection{srcBox->collectionId()}, items, this);
         }
         if (const auto dstBox = unifiedMailboxForSource(dstCollection.id())) {
             // Move destination collection is our source, link the Item into a box
             new Akonadi::LinkJob(Akonadi::Collection{dstBox->collectionId()}, items, this);
         }
     });
 
     connect(&mMonitor, &Akonadi::Monitor::collectionRemoved,
             this, [this](const Akonadi::Collection &col) {
         ReplayNextOnExit replayNext(mMonitor);
 
         if (auto box = unifiedMailboxForSource(col.id())) {
             box->removeSourceCollection(col.id());
             mMonitor.setCollectionMonitored(col, false);
             if (box->sourceCollections().isEmpty()) {
                 removeBox(box->id());
             }
             saveBoxes();
             // No need to resync the box collection, the linked Items got removed by Akonadi
         } else {
             qCWarning(UNIFIEDMAILBOXAGENT_LOG) << "Received notification about removal of Collection" << col.id() << "which we don't monitor";
         }
     });
     connect(&mMonitor, qOverload<const Akonadi::Collection &, const QSet<QByteArray> &>(&Akonadi::Monitor::collectionChanged),
             this, [this](const Akonadi::Collection &col, const QSet<QByteArray> &parts) {
         ReplayNextOnExit replayNext(mMonitor);
 
         qCDebug(UNIFIEDMAILBOXAGENT_LOG) << "Collection changed:" << parts;
         if (!parts.contains(Akonadi::SpecialCollectionAttribute().type())) {
             return;
         }
 
         if (col.hasAttribute<Akonadi::SpecialCollectionAttribute>()) {
             const auto srcBox = unregisterSpecialSourceCollection(col.id());
             const auto dstBox = registerSpecialSourceCollection(col);
             if (srcBox == dstBox) {
                 return;
             }
 
             saveBoxes();
 
             if (srcBox && srcBox->sourceCollections().isEmpty()) {
                 removeBox(srcBox->id());
                 return;
             }
 
             if (srcBox) {
                 Q_EMIT updateBox(srcBox);
             }
             if (dstBox) {
                 Q_EMIT updateBox(dstBox);
             }
         } else {
             if (const auto box = unregisterSpecialSourceCollection(col.id())) {
                 saveBoxes();
                 if (box->sourceCollections().isEmpty()) {
                     removeBox(box->id());
                 } else {
                     Q_EMIT updateBox(box);
                 }
             }
         }
     });
 }
 
 UnifiedMailboxManager::~UnifiedMailboxManager()
 {
 }
 
 Akonadi::ChangeRecorder &UnifiedMailboxManager::changeRecorder()
 {
     return mMonitor;
 }
 
 void UnifiedMailboxManager::loadBoxes(FinishedCallback &&finishedCb)
 {
     qCDebug(UNIFIEDMAILBOXAGENT_LOG) << "loading boxes";
     const auto group = mConfig->group("UnifiedMailboxes");
     const auto boxGroups = group.groupList();
     for (const auto &boxGroupName : boxGroups) {
         const auto boxGroup = group.group(boxGroupName);
         auto box = std::make_unique<UnifiedMailbox>();
         box->load(boxGroup);
         insertBox(std::move(box));
     }
 
     const auto cb = [this, finishedCb = std::move(finishedCb)]() {
                         qCDebug(UNIFIEDMAILBOXAGENT_LOG) << "Finished callback: enabling change recorder";
                         // Only now start processing changes from change recorder
                         connect(&mMonitor, &Akonadi::ChangeRecorder::changesAdded, &mMonitor, &Akonadi::ChangeRecorder::replayNext, Qt::QueuedConnection);
                         // And start replaying any potentially pending notification
                         QTimer::singleShot(0, &mMonitor, &Akonadi::ChangeRecorder::replayNext);
 
                         if (finishedCb) {
                             finishedCb();
                         }
                     };
 
     qCDebug(UNIFIEDMAILBOXAGENT_LOG) << "Loaded" << mMailboxes.size() << "boxes from config";
 
     if (mMailboxes.empty()) {
         createDefaultBoxes(std::move(cb));
     } else {
         discoverBoxCollections(std::move(cb));
     }
 }
 
 void UnifiedMailboxManager::saveBoxes()
 {
     auto group = mConfig->group("UnifiedMailboxes");
     const auto currentGroups = group.groupList();
     for (const auto &groupName : currentGroups) {
         group.deleteGroup(groupName);
     }
     for (const auto &boxIt : mMailboxes) {
         auto boxGroup = group.group(boxIt.second->id());
         boxIt.second->save(boxGroup);
     }
     mConfig->sync();
     mConfig->reparseConfiguration();
 }
 
 void UnifiedMailboxManager::insertBox(std::unique_ptr<UnifiedMailbox> box)
 {
     auto it = mMailboxes.emplace(std::make_pair(box->id(), std::move(box)));
     it.first->second->attachManager(this);
 }
 
 void UnifiedMailboxManager::removeBox(const QString &id)
 {
     auto box = std::find_if(mMailboxes.begin(), mMailboxes.end(),
                             [&id](const std::pair<const QString, std::unique_ptr<UnifiedMailbox> > &box) {
         return box.second->id() == id;
     });
     if (box == mMailboxes.end()) {
         return;
     }
 
     box->second->attachManager(nullptr);
     mMailboxes.erase(box);
 }
 
 UnifiedMailbox *UnifiedMailboxManager::unifiedMailboxForSource(qint64 source) const
 {
     const auto box = mSourceToBoxMap.find(source);
     if (box == mSourceToBoxMap.cend()) {
         return {};
     }
     return box->second;
 }
 
 UnifiedMailbox *UnifiedMailboxManager::unifiedMailboxFromCollection(const Akonadi::Collection &col) const
 {
     if (!isUnifiedMailbox(col)) {
         return nullptr;
     }
 
     const auto box = mMailboxes.find(col.name());
     if (box == mMailboxes.cend()) {
         return {};
     }
     return box->second.get();
 }
 
 void UnifiedMailboxManager::createDefaultBoxes(FinishedCallback &&finishedCb)
 {
     if (!Settings::self()->createDefaultBoxes()) {
         return;
     }
     // First build empty boxes
     auto inbox = std::make_unique<UnifiedMailbox>();
     inbox->attachManager(this);
     inbox->setId(Common::InboxBoxId);
     inbox->setName(i18n("Inbox"));
     inbox->setIcon(QStringLiteral("mail-folder-inbox"));
     insertBox(std::move(inbox));
 
     auto sent = std::make_unique<UnifiedMailbox>();
     sent->attachManager(this);
     sent->setId(Common::SentBoxId);
     sent->setName(i18n("Sent"));
     sent->setIcon(QStringLiteral("mail-folder-sent"));
     insertBox(std::move(sent));
 
     auto drafts = std::make_unique<UnifiedMailbox>();
     drafts->attachManager(this);
     drafts->setId(Common::DraftsBoxId);
     drafts->setName(i18n("Drafts"));
     drafts->setIcon(QStringLiteral("document-properties"));
     insertBox(std::move(drafts));
 
     auto list = new Akonadi::CollectionFetchJob(Akonadi::Collection::root(), Akonadi::CollectionFetchJob::Recursive, this);
     list->fetchScope().fetchAttribute<Akonadi::SpecialCollectionAttribute>();
     list->fetchScope().setContentMimeTypes({QStringLiteral("message/rfc822")});
 #ifdef UNIT_TESTS
     list->fetchScope().setAncestorRetrieval(Akonadi::CollectionFetchScope::Parent);
 #else
     list->fetchScope().setAncestorRetrieval(Akonadi::CollectionFetchScope::None);
 #endif
     connect(list, &Akonadi::CollectionFetchJob::collectionsReceived,
             this, [this](const Akonadi::Collection::List &list) {
         for (const auto &col : list) {
             if (isUnifiedMailbox(col)) {
                 continue;
             }
 
             try {
                 switch (Akonadi::SpecialMailCollections::self()->specialCollectionType(col)) {
                 case Akonadi::SpecialMailCollections::Inbox:
                     mMailboxes.at(Common::InboxBoxId)->addSourceCollection(col.id());
                     break;
                 case Akonadi::SpecialMailCollections::SentMail:
                     mMailboxes.at(Common::SentBoxId)->addSourceCollection(col.id());
                     break;
                 case Akonadi::SpecialMailCollections::Drafts:
                     mMailboxes.at(Common::DraftsBoxId)->addSourceCollection(col.id());
                     break;
                 default:
                     continue;
                 }
             } catch (const std::out_of_range &) {
                 qCWarning(UNIFIEDMAILBOXAGENT_LOG) << "Failed to find a special unified mailbox for source collection" << col.id();
                 continue;
             }
         }
     });
     connect(list, &Akonadi::CollectionFetchJob::result,
             this, [this, finishedCb = std::move(finishedCb)]() {
         saveBoxes();
         if (finishedCb) {
             finishedCb();
         }
     });
 #ifndef UNIT_TESTS
     Settings::self()->setCreateDefaultBoxes(false);
     Settings::self()->save();
 #endif
 }
 
 void UnifiedMailboxManager::discoverBoxCollections(FinishedCallback &&finishedCb)
 {
     auto list = new Akonadi::CollectionFetchJob(Akonadi::Collection::root(), Akonadi::CollectionFetchJob::Recursive, this);
 #ifdef UNIT_TESTS
     list->fetchScope().setAncestorRetrieval(Akonadi::CollectionFetchScope::Parent);
 #else
     list->fetchScope().setResource(Common::AgentIdentifier);
 #endif
     connect(list, &Akonadi::CollectionFetchJob::collectionsReceived,
             this, [this](const Akonadi::Collection::List &list) {
         for (const auto &col : list) {
             if (!isUnifiedMailbox(col) || col.parentCollection() == Akonadi::Collection::root()) {
                 continue;
             }
-
-            mMailboxes.at(col.name())->setCollectionId(col.id());
+            const auto it = mMailboxes.find(col.name());
+            if (it == mMailboxes.end()) {
+                qCWarning(UNIFIEDMAILBOXAGENT_LOG) << "Failed to find an unified mailbox for source collection" << col.id();
+            } else {
+                it->second->setCollectionId(col.id());
+            }
         }
     });
     if (finishedCb) {
         connect(list, &Akonadi::CollectionFetchJob::result, this, finishedCb);
     }
 }
 
 const UnifiedMailbox *UnifiedMailboxManager::registerSpecialSourceCollection(const Akonadi::Collection &col)
 {
     // This is slightly awkward, wold be better if we could use SpecialMailCollections,
     // but it also relies on Monitor internally, so there's a possible race condition
     // between our ChangeRecorder and SpecialMailCollections' Monitor
     auto attr = col.attribute<Akonadi::SpecialCollectionAttribute>();
     Q_ASSERT(attr);
     if (!attr) {
         return {};
     }
 
     decltype(mMailboxes)::iterator box;
     if (attr->collectionType() == Common::SpecialCollectionInbox) {
         box = mMailboxes.find(Common::InboxBoxId);
     } else if (attr->collectionType() == Common::SpecialCollectionSentMail) {
         box = mMailboxes.find(Common::SentBoxId);
     } else if (attr->collectionType() == Common::SpecialCollectionDrafts) {
         box = mMailboxes.find(Common::DraftsBoxId);
     }
     if (box == mMailboxes.end()) {
         return {};
     }
 
     box->second->addSourceCollection(col.id());
     return box->second.get();
 }
 
 const UnifiedMailbox *UnifiedMailboxManager::unregisterSpecialSourceCollection(qint64 colId)
 {
     auto box = unifiedMailboxForSource(colId);
     if (!box) {
         return {};
     }
 
     if (!box->isSpecial()) {
         qCDebug(UNIFIEDMAILBOXAGENT_LOG) << colId << "does not belong to a special unified box" << box->id();
         return {};
     }
 
     box->removeSourceCollection(colId);
     return box;
 }