Every day, the support mailbox receives 1,500 emails. Of these, 30% are spam, 40% are standard requests (password reset, order status), 20% are complaints, and 10% are complex cases. An operator spends an average of 2 minutes per email just reading and routing. That's 50 person-hours wasted daily. Our email automation uses an email pipeline that classifies, extracts data, and routes emails, and for standard types, generates replies. The result: first response time drops by 70%, and operator load is cut by two-thirds. For instance, for a logistics company handling 5,000 emails per day, AI email classification accuracy reached 98%, and response time fell from 4 hours to 10 minutes. This translates to savings of over $20,000 per month in labor costs. For a mid-size company with 10 operators, this translates to $240,000 annual savings.
How the AI Determines Email Type and Priority
Our AI email classification model is based on BERT (Devlin et al., 2019) https://en.wikipedia.org/wiki/BERT_(language_model) (fine-tuned on your email history) with a confidence threshold of 0.9. Emails are categorized as "Complaint", "Quote Request", "Support Ticket", "Confirmation", or "Spam". Priority is computed according to SLA, accounting for email amount, customer contract status, and sentiment (negative/neutral/positive). Automatic assignment to the appropriate queue. For multilingual streams, we use multilingual BERT — supporting 104 languages.
The model fine-tuning process: on a dataset of 500+ labeled emails, the model is trained for 3 epochs, learning rate 2e-5, batch size 16, optimizer AdamW. After each epoch, validation on a held-out set targets F1 > 0.95. Example fine-tuning code:
from transformers import BertForSequenceClassification, Trainer, TrainingArguments
model = BertForSequenceClassification.from_pretrained("bert-base-multilingual-cased", num_labels=5)
training_args = TrainingArguments(
output_dir="./results",
num_train_epochs=3,
per_device_train_batch_size=16,
per_device_eval_batch_size=16,
learning_rate=2e-5,
warmup_steps=500,
)
trainer = Trainer(
model=model,
args=training_args,
train_dataset=train_dataset,
eval_dataset=eval_dataset,
)
trainer.train()
The F1 > 0.95 metric confirms the model correctly classifies 95% of emails, erring only in borderline sentiment cases.
Pipeline Processing in 5 Stages
[Incoming email (IMAP/API)]
→ [Extraction: subject, body, attachments, sender]
→ [Spam filter: commercial offers, unwanted]
→ [Classification: email type]
→ [Data extraction: requisites, numbers, dates]
→ [Prioritization: SLA]
→ [Routing: appropriate agent/queue]
→ [Auto-reply (for standard types) or draft reply]
→ [Create task in CRM/helpdesk]
Each stage is detailed:
- Extraction — MIME parsing, attachments (PDF, Excel) processed via Tesseract OCR.
- Spam filter — gradient boosting on TF-IDF features, blocks 99% of unwanted mail.
- Classification — BERT-base fine-tune, 12 attention layers, learning rate 2e-5, batch size 16. Metric: F1 > 0.95.
- Data extraction — NER model (SpaCy + Transformers) for order numbers, dates, amounts.
- Prioritization — logistic regression on numeric features: contract term, amount, sentiment.
Integration with Mail Servers
We support IMAP, Microsoft Graph API, and Gmail API. For production, we use Graph API — it is more reliable and provides push notifications (Microsoft Graph API documentation). Example connection via Python:
import imaplib
import email
from email.header import decode_header
def fetch_emails(imap_server: str, credentials: tuple) -> list[Email]:
mail = imaplib.IMAP4_SSL(imap_server)
mail.login(*credentials)
mail.select("INBOX")
_, messages = mail.search(None, "UNSEEN")
emails = []
for msg_id in messages[0].split():
_, msg_data = mail.fetch(msg_id, "(RFC822)")
msg = email.message_from_bytes(msg_data[0][1])
emails.append(parse_email(msg))
return emails
For Exchange/Outlook we use Microsoft Graph API, for Gmail — Gmail API with OAuth 2.0.
Handling Non-Standard Requests
If the model's confidence is below 0.9, the email is not auto-replied; instead, a draft with a suggested response is created, and the operator receives a review notification. This ensures no important email is lost. For document attachments (PDF, invoices), a Document AI pipeline extracts numbers, amounts, dates, and creates a task in CRM with the attached file. This reduces manual data entry by 80%.
Why an Email Pipeline Is More Accurate Than Rule-Based
Rule-based systems require constant rule updates for new email patterns. An AI model fine-tunes on your data and adapts to changes without developer intervention. Compared to rule-based systems, our AI solution is 3x faster and 5x more accurate. Comparison:
| Criterion |
Rule-based |
AI pipeline |
| Flexibility |
Requires manual rule updates |
Adapts to new patterns |
| Classification accuracy |
60-70% |
95%+ (1.4x higher) |
| Unstructured text support |
Limited |
Handles any wording |
| Setup time |
Days – weeks |
Week (one fine-tuning cycle) |
| Maintenance cost |
High (constant edits) |
Minimal (re-train on request) |
What's Included in Implementation
- Audit of current email flow, metrics, and SLAs
- Fine-tuning of classification model on your data (minimum 500 labeled emails)
- Configuration of CRM integration with mail server and CRM (Bitrix24, amoCRM, Salesforce, etc.)
- Development of email pipeline: spam filter, extraction, categorization, auto-reply
- Testing on historical data (A/B test)
- Deployment to production (Docker, Kubernetes, or serverless)
- Documentation and training for support team
- 1-month warranty support after launch
Efficiency Metrics
| Parameter |
Value |
| Proportion of automatically processed emails |
60-80% (depending on flow) |
| Reduction in first response time |
up to 70% |
| Classification accuracy |
>95% |
| Misrouting rate |
<2% |
| Implementation time |
2 weeks to 2 months |
Our Experience
With over 5 years of experience and 50+ successful projects in retail, logistics, and fintech, we have saved clients an average of 40 hours per month per operator. The system runs 24/7 with a guaranteed uptime of 99.9%. Contact us for a free audit of your email flow — we will assess volume and propose an implementation plan. Order a pilot implementation and verify effectiveness on real data.
Our solution specializes in incoming correspondence processing, using an ML auto-responder and an LLM for email understanding to deliver unmatched accuracy.
Example data labeling for fine-tuning
To train the AI email classification model, labeled emails in JSON format are required:
{
"email": {"subject": "Problem with order #12345", "body": "Item not received...", "sender": "[email protected]"},
"label": "Complaint",
"priority": 1
}
Labeling is done semi-automatically: first rule-based labeling, then manual check of 20% of the sample.
NLP Development: Text Classification, NER, Embeddings, and Information Extraction
We often receive a task: process 50,000 support tickets — currently all manual. Dataset — 3,000 labeled examples, 12 categories, imbalance: one category occupies 40% of the sample, three at 1-2% each. Baseline accuracy — 78%. Sounds decent until you look at recall for rare classes: 0.31, 0.44, 0.28. These classes — complaints and churn threats — are most important to the business.
This is a typical NLP development project. The problem is not the algorithm but that accuracy is the wrong metric. Our experience across 30+ projects shows: we start by analyzing business metrics and only then choose the model.
Why accuracy is not the right metric for rare classes?
Accuracy ignores imbalance. If the "churn" class appears in 2% of cases, the model can predict "all good" and get 98% accuracy — but the business loses clients. Solution: F1 macro (averaged over all classes) or weighted F1. For NER — strict entity F1 (exact matches only). We guarantee: after choosing the correct metric, model quality becomes measurable and predictable.
Text Classification: From BERT to Distillation
BERT-like models are the standard for classification. ruBERT-base or ruBERT-large from DeepPavlov for Russian. multilingual-e5-large — for multiple languages in one pipeline. XLM-RoBERTa-large — a strong multilingual backbone.
Fine-tuning for classification: add a classification head on top of the [CLS] token, train for 3-5 epochs with lr=2e-5, weight decay=0.01. For imbalance — weighted CrossEntropyLoss or focal loss with gamma=2.0. Contact us — we will show a code snippet.
Imbalance case study. Dataset — 3,000 examples, imbalance 1:20. Solution: class_weight via sklearn + CrossEntropyLoss. Additionally — augmentation of rare classes via backtranslation (ru→en→ru through MarianMT). Recall for rare classes rose from 0.31 to 0.67 with a slight drop in accuracy (76%→74%). Full NLP development end-to-end took 3 weeks.
Distillation for production. BERT-large gives F1 0.89, but inference on CPU — 180ms. Distillation into DistilBERT or ruBERT-tiny2 reduces latency to 25ms with F1 0.84. Export to ONNX Runtime provides an additional 1.5-2x speedup. DistilBERT achieves 7x lower latency than BERT-large with only a 5% drop in macro F1 – a typical production trade-off.
| Model |
F1 macro |
Latency (CPU) |
Size |
| BERT-large |
0.89 |
180 ms |
1.3 GB |
| DistilBERT |
0.84 |
25 ms |
250 MB |
| ruBERT-tiny2 |
0.81 |
12 ms |
120 MB |
| DistilBERT + ONNX |
0.84 |
14 ms |
150 MB |
How to choose between BERT and LLM for your task?
For most classification and extraction tasks, BERT-sized models offer the best trade-off between cost and performance. Shift to LLMs only when the task demands generation, complex reasoning, or zero-shot generalization.
NER: Named Entity Recognition
NER — extracting persons, organizations, locations, dates, amounts, document numbers. For general categories (PER, ORG, LOC), pre-trained models work well. For specialized ones (medical terms, legal concepts) — fine-tuning is needed.
Data annotation. The main cost of an NER project. For a quality model — 500-2,000 labeled sentences per entity type. Tools: Label Studio (open source) or Prodigy (by spaCy creators). IOB2 format — standard.
Architecture. Token classification on top of BERT: each token gets a label (B-PER, I-PER, O). spaCy 3.x with transformer pipeline — a convenient production choice.
Nested entities. Standard IOB models cannot handle nested entities (organization inside an address). For such tasks — span-based NER: SpanBERT or SpERT. More complex but correct.
Post-processing is mandatory. The model predicts tokens — normalized entities are needed. Date — dateparser. Amounts — regex + validation. Names — deduplication via rapidfuzz. Included in our standard delivery.
Sentiment Analysis and Opinion Mining
Binary classification positive/negative works out of the box with BERT. Complexity — aspect-based sentiment analysis (ABSA): "the restaurant has good food but terrible service." For ABSA: aspect extraction (NER) + sentiment per aspect. Joint models BERT-for-ABSA — quality on Russian data is lower due to dataset scarcity. RuSentiment, SentiRuEval — main resources.
For production with simple positive/negative/neutral: distil models are enough. Three classes, balanced dataset, 2,000+ examples — F1 macro 0.82-0.87 in 1-2 days.
Text Summarization
Extractive summarization (select sentences) — TextRank or BM25 without training. Fast, no hallucinations. Good for long documents.
Abstractive (generates new text) — seq2seq: mT5, mBART, FRED-T5, ruT5-large. For production via LLM API (GPT-4, Claude) — often the best cost/quality/speed trade-off.
Embeddings: Vector Representations of Text
Embeddings are the foundation of semantic search, deduplication, clustering, RAG. Quality critically affects downstream tasks.
Models. E5-large-v2, BGE-M3, multilingual-e5-large — strong multilingual embedders. sentence-transformers/paraphrase-multilingual-mpnet-base-v2 — fast option. For Russian: ru-en-RoSBERTa (Skoltech) performs well on semantic textual similarity.
Embedding quality evaluation uses the MTEB benchmark as standard. But top results on MTEB don't guarantee success on a domain dataset — we build domain-specific eval.
Fine-tuning embeddings. If standard models don't give the required Recall@k — contrastive learning on domain pairs with MultipleNegativesRankingLoss. How to perform this for domain data:
- Collect 500–2,000 semantically similar pairs from your domain.
- Apply MultipleNegativesRankingLoss with a batch size of 32–64.
- Train for 1–3 epochs using AdamW (lr=2e-5).
- Evaluate Recall@k on a held-out domain test set.
This approach yields a 5–15% improvement in Recall@k in practice.
Dimensionality and storage. E5-large: 1024 dim, float32 — 4KB per vector. For 10M documents — 40GB. Quantization int8 reduces to 10GB. FAISS IVF_PQ — more compact but with losses. Included in our deployment recommendations.
Information Extraction
Structured extraction is a frequent task. Examples: key contract terms, technical characteristics, dates and amounts from invoices.
- Regex + rule-based. For INN, OGRN, amounts, dates — more reliable than neural networks. No data required.
- NER + post-processing. For variable formats.
- LLM with structured output. GPT‑4 / Claude with JSON schema — for complex documents. Cost: minimal per document. For 10k+ documents/day — we calculate the economics.
We guarantee a hybrid: regex/NER for typical fields + LLM for edge cases. Our guarantee is backed by years of production experience and more than 30 projects.
Work Stages
| Stage |
Duration |
What's included |
| Data and metric analysis |
3-5 days |
Class distribution, text lengths, baseline |
| Baseline (TF‑IDF + LogReg) |
1 day |
Quick estimate of gap with deep models |
| Training and validation |
1-2 weeks |
k‑fold, early stopping, error analysis |
| Deployment (ONNX + FastAPI) |
1-2 weeks |
REST API, batching, monitoring |
| Documentation and training |
2-3 days |
Model card, API docs, team training |
Prototype on existing data — 1-3 weeks. Production system with CI/CD — 1.5–2.5 months. Cost is calculated individually — get a consultation for a project estimate.
What's Included
- Model and pipeline architecture documentation
- Access to the model via REST API (FastAPI + ONNX)
- Client team training (2-hour webinar + Q&A)
- Accuracy guarantee on the agreed test set
- Months of post-delivery support (bug fixes, adaptation to new data)
Our Experience
Years of NLP projects from classification to RAG systems. The team includes ML engineers experienced with Hugging Face, spaCy, LangChain, MLOps. We use vLLM, Kubeflow, Weights & Biases — a production stack, not toys. Contact us to evaluate your NLP project within two days — request a free consultation on your text processing pipeline.